SCHEDULE 13G

Amendment No. 7 
Gildan Activewear Incorporated 
Class A Subordinate Voting Shares 
Cusip #375916103 


Cusip #375916103 
Item 1:	Reporting Person - FMR Corp.
Item 4:	Delaware
Item 5:	0 
Item 6:	0 
Item 7:	2,595,500 
Item 8:	0 
Item 9:	2,595,500 
Item 11:	8.739% 
Item 12:	    HC


Cusip #375916103  
Item 1:	Reporting Person - Edward C. Johnson 3d 
Item 4:	United States of America
Item 5:	0 
Item 6:	0 
Item 7:	2,595,500 
Item 8:	0 
Item 9:	2,595,500 
Item 11:	8.739% 
Item 12:	IN 


Cusip #375916103 
Item 1:	Reporting Person - Abigail P. Johnson 
Item 4:	United States of America
Item 5:	0 
Item 6:	0 
Item 7:	2,595,500 
Item 8:	0 
Item 9:	2,595,500 
Item 11:	8.739% 
Item 12:	    IN



	SCHEDULE 13G - TO BE INCLUDED IN 
STATEMENTS
	FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)




Item 1(a).	Name of Issuer:	

		Gildan Activewear Incorporated 

Item 1(b).	Name of Issuer's Principal Executive Offices:

		725 Montee de Liesse
		Ville Saint-Laurent 
		Quebec, H4T 1P5  Canada
		  

Item 2(a).	Name of Person Filing: 

		FMR Corp.

Item 2(b).	Address or Principal Business Office or, if None, 
Residence:

		82 Devonshire Street, Boston, 
Massachusetts  02109

Item 2(c).	Citizenship:

		Not applicable

Item 2(d).	Title of Class of Securities:

		Class A Subordinate Voting Shares 

Item 2(e).	CUSIP Number:  

		375916103 

Item 3.	This statement is filed pursuant to Rule 13d-1(b) or 13d-2(b) 
and the person filing, FMR Corp., is a parent holding company 
in accordance with Section 240.13d-1(b)(ii)(G).  (Note:  See 
Item 7).

Item 4.	Ownership

	(a)	Amount Beneficially Owned:	2,595,500 

	(b)	Percent of Class:	8.739% 

	(c)	Number of shares as to which such 
person has:  

	(i)	sole power to vote or to direct 
the vote:	0 

	(ii)	shared power to vote or to 
direct the vote:	0 

	(iii)	sole power to dispose or to 
direct the disposition of:	2,595,500 

	(iv)	shared power to dispose or to 
direct the disposition of:	0 



Item 5.	Ownership of Five Percent or Less of a Class.

	Not applicable.

Item 6.	Ownership of More than Five Percent on Behalf of Another 
Person.

	Various persons have the right to receive or the power to 
direct the receipt of dividends from, or the proceeds from the 
sale of, the Class A Subordinate Voting Shares of Gildan 
Activewear Incorporated.  The interest of one person, Fidelity 
Low Priced Stock Fund, an investment company registered 
under the Investment Company Act of 1940, in the Class A 
Subordinate Voting Shares of Gildan Activewear 
Incorporated, amounted to 2,595,400 shares or 8.739% of the 
total outstanding Class A Subordinate Voting Shares at 
December 31, 2004. 

Item 7.	Identification and Classification of the Subsidiary Which 
Acquired the Security Being Reported on By the Parent 
Holding Company.

	See attached Exhibit(s) A, B. 

Item 8.	Identification and Classification of Members of 
the Group.

	Not Applicable. See attached Exhibit A. 

Item 9.	Notice of Dissolution of Group.

	Not applicable.

Item 10.	Certification.

	By signing below I certify that, to the best of my knowledge 
and belief, the securities referred to above were acquired in the 
ordinary course of business and were not acquired for the 
purpose of and do not have the effect of changing or 
influencing the control of the issuer of such securities and 
were not acquired in connection with or as a participant in any 
transaction having such purpose or effect.

Signature

	After reasonable inquiry and to the best of my knowledge and 
belief, I certify that the information set forth in this Schedule 
13G in connection with FMR Corp.'s beneficial ownership of 
the Class A Subordinate Voting Shares of Gildan Activewear 
Incorporated at December 31, 2004 is true, complete and 
correct. 

February 14, 2005 			
Date

/s/Eric D. Roiter				
Signature

Eric D. Roiter				
Duly authorized under Power of Attorney
dated December 30, 1997 by and on behalf
of FMR Corp. and its direct and indirect
subsidiaries


	SCHEDULE 13G - TO BE INCLUDED IN 
STATEMENTS
	FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)



	Pursuant to the instructions in Item 7 of Schedule 
13G, Fidelity Management & Research Company 
("Fidelity"), 82 Devonshire Street, Boston, Massachusetts 
02109, a wholly-owned subsidiary of FMR Corp. and an 
investment adviser registered under Section 203 of the 
Investment Advisers Act of 1940, is the beneficial owner of 
2,595,500 shares or 8.739% of the Class A Subordinate 
Voting Shares outstanding of Gildan Activewear 
Incorporated  ("the Company") as a result of acting as 
investment adviser to various investment companies 
registered under Section 8 of the Investment Company Act of 
1940.

	The ownership of one investment company, Fidelity 
Low Priced Stock Fund, amounted to 2,595,400 shares or 
8.739% of the Class A Subordinate Voting Shares 
outstanding. Fidelity Low Priced Stock Fund has its principal 
business office at 82 Devonshire Street, Boston, 
Massachusetts 02109.

	Edward C. Johnson 3d, FMR Corp., through its 
control of Fidelity, and the funds each has sole power to 
dispose of the 2,595,500 shares owned by the Funds.

	Neither FMR Corp. nor Edward C. Johnson 3d, 
Chairman of FMR Corp., has the sole power to vote or direct 
the voting of the shares owned directly by the Fidelity Funds, 
which power resides with the Funds' Boards of Trustees.  
Fidelity carries out the voting of the shares under written 
guidelines established by the Funds' Boards of Trustees.

	Members of the Edward C. Johnson 3d family are the 
predominant owners of Class B shares of common stock of 
FMR Corp., representing approximately 49% of the voting 
power of FMR Corp.  Mr. Johnson 3d owns 12.0% and 
Abigail Johnson owns 24.5% of the aggregate outstanding 
voting stock of FMR Corp.  Mr. Johnson 3d is Chairman of 
FMR Corp. and Abigail P. Johnson is a Director of FMR 
Corp.  The Johnson family group and all other Class B 
shareholders have entered into a shareholders' voting 
agreement under which all Class B shares will be voted in 
accordance with the majority vote of Class B shares.  
Accordingly, through their ownership of voting common 
stock and the execution of the shareholders' voting 
agreement, members of the Johnson family may be deemed, 
under the Investment Company Act of 1940, to form a 
controlling group with respect to FMR Corp.

 


	SCHEDULE 13G - TO BE INCLUDED IN 
STATEMENTS
	FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)
	RULE 13d-1(f)(1)  AGREEMENT

	The undersigned persons, on February 14, 2005, agree 
and consent to the joint filing on their behalf of this Schedule 
13G in connection with their beneficial ownership of the Class 
A Subordinate Voting Shares of Gildan Activewear 
Incorporated at December 31, 2004.

	FMR Corp.

	By /s/ Eric D. Roiter			
	Eric D. Roiter
	Duly authorized under Power of Attorney
	dated December 30, 1997, by and on behalf
	of FMR Corp. and its direct and indirect 
	subsidiaries

	Edward C. Johnson 3d

	By /s/ Eric D. Roiter			
	Eric D. Roiter
	Duly authorized under Power of Attorney
	dated December 30, 1997, by and on behalf
	of Edward C. Johnson 3d

	Abigail P. Johnson

	By /s/ Eric D. Roiter			
	Eric D. Roiter
	Duly authorized under Power of Attorney
	dated December 30, 1997, by and on behalf
	of Abigail P. Johnson

	Fidelity Management & Research Company

	By /s/ Eric D. Roiter			
	Eric D. Roiter
	Senior V.P. and General Counsel

	Fidelity Low Priced Stock Fund

	By /s/ Eric D. Roiter			
	Eric D. Roiter
	Secretary