Income Taxes (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties
Beginning Balance	$ (45,936)	$ (27,008)	$ (23,697)
Reduction based on tax positions related to a prior year	1,851		(4,557)
Additions based on tax positions related to the prior year		(15,764)
Additions based on tax positions related to the current year	(900)	(3,164)	(4,340)
Reductions as a result of a lapse of the applicable statute of limitations	3,744		5,586
Ending Balance	(41,241)	(45,936)	(27,008)
Long Term Tax Receivable [Member]
Reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties
Beginning Balance	7,036	6,471	5,534
Reduction based on tax positions related to a prior year	0
Additions based on tax positions related to the current year	145	565	2,441
Reductions as a result of a lapse of the applicable statute of limitations	0		(1,504)
Ending Balance	7,181	7,036	6,471
Long Term Tax Payable [Member]
Reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties
Beginning Balance	(52,972)	(33,479)	(29,231)
Reduction based on tax positions related to a prior year	1,851		(4,557)
Additions based on tax positions related to the prior year		(15,764)
Additions based on tax positions related to the current year	(1,045)	(3,729)	(6,781)
Reductions as a result of a lapse of the applicable statute of limitations	3,744		7,090
Ending Balance	$ (48,422)	$ (52,972)	$ (33,479)