SECURITIES REPURCHASE PROGRAM (Details) (USD $)	1 Months Ended			3 Months Ended	9 Months Ended			1 Months Ended			1 Months Ended	9 Months Ended
	Aug. 31, 2011	May 31, 2011	Nov. 30, 2010	Sep. 30, 2011	Sep. 30, 2011	Sep. 30, 2011 5.375% Convertible notes due August 2014	Sep. 30, 2011 5.375% Convertible notes due August 2014 Repurchase of debt	May 31, 2011 Common shares	Mar. 31, 2011 Common shares	Sep. 30, 2011 Common shares	Nov. 30, 2011 Renewed Securities Repurchase Program	Sep. 30, 2011 Renewed Securities Repurchase Program
Securities repurchase program
Aggregate maximum amount authorized under the "securities repurchase program"	$ 1,800,000,000		$ 1,500,000,000								$ 1,500,000,000
Increased authorized amount under the securities repurchase program	300,000,000
Aggregate principal amount of notes repurchased						177,200,000
Stated interest rate (as a percent)						5.375%
Aggregate purchase price of convertible notes				202,587,000	541,600,000	549,900,000
Carrying amount of convertible notes						153,200,000
Unamortized deferred financing costs						4,900,000
Estimated fair value of convertible notes						181,400,000
Loss on extinguishment of debt				(10,315,000)	(33,325,000)	28,200,000
Difference between the estimated fair value and the repurchase price of securities						368,500,000
Difference between the estimated fair value and the purchase price of securities charged to additional paid-in capital						28,700,000
Difference between the estimated fair value and the purchase price of securities charged to accumulated deficit						339,800,000
Estimated amount receivable in relation to withholding taxes on repurchase										24,200,000
Accreted interest on repurchase of convertible debt				3,362,000	8,363,000	8,300,000
Premium above the carrying value on repurchase of convertible debt						5,400,000
Aggregate principal amount of the 5.375% Convertible Notes repurchased in connection with the securities repurchase program						303,500,000	24,500,000
Aggregate consideration on the 5.375% Convertible Notes repurchased in connection with the securities repurchase program						809,100,000	63,600,000
Convertible notes and shares repurchased												1,400,000,000
Convertible notes and common shares repurchased (in shares)								4,498,180	7,366,419
Aggregate repurchase price of entity's common shares repurchased		224,814,000		74,556,000	574,120,000			224,800,000	274,800,000
Aggregate common shares repurchased in connection with the securities repurchase program (in shares)										15,969,599
Aggregate consideration on Company's common shares repurchased in connection with the securities repurchase program										$ 634,200,000