Significant Accounting Policies - Revision to Statement of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2011	Mar. 31, 2010	Jun. 30, 2011	Jun. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Scenario, Previously Reported [Member] | Net cash flows provided by operating activities
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year	$ 44,006	$ 36,544	$ 164,964	$ 150,468	$ 252,145	$ 248,890	$ 362,324
Scenario, Previously Reported [Member] | Net cash provided by (used in) financing activities
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year	(1,716)	(29,036)	(36,139)	(157,205)	1,084,637	(86,923)	(101,401)
Scenario, Previously Reported [Member] | Net cash used in investing activities [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year		(15,711)		(27,182)		(51,345)	(129,490)
Scenario, Previously Reported [Member] | Effect of exchange rate changes on cash [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year		(37,128)		(76,082)		(26,727)	(41,743)
Restatement Adjustment [Member] | Net cash flows provided by operating activities
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year	723	7,731	1,545	8,199	2,687	8,448	15,137
Restatement Adjustment [Member] | Net cash provided by (used in) financing activities
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year	(723)	(564)	(1,545)	(1,032)	(2,687)	(1,281)	(1,635)
Restatement Adjustment [Member] | Net cash used in investing activities [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year		(18,568)		(18,568)		(18,568)	(34,978)
Restatement Adjustment [Member] | Effect of exchange rate changes on cash [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year		11,401		11,401		11,401	21,476
Scenario, Actual [Member] | Net cash flows provided by operating activities
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year	44,729	44,275	166,509	158,667	254,832	257,338	377,461
Scenario, Actual [Member] | Net cash provided by (used in) financing activities
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year	(2,439)	(29,600)	(37,684)	(158,237)	1,081,950	(88,204)	(103,036)
Scenario, Actual [Member] | Net cash used in investing activities [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year		(34,279)		(45,750)		(69,913)	(164,468)
Scenario, Actual [Member] | Effect of exchange rate changes on cash [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Error Corrections and Prior Period Adjustments, Interim Periods of Fiscal Year		$ (25,727)		$ (64,681)		$ (15,326)	$ (20,267)