Income Tax Expense (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Valuation allowance
Valuation allowance		$ 149,600
Valuation allowance	0
Net increase in U.S. and foreign valuation allowances	1,483	139,662
Deferred Tax Assets | U.S. Federal
Valuation allowance
Valuation allowance	146,681	122,317
Valuation allowance	0
Deferred Tax Assets | State
Valuation allowance
Valuation allowance	29,170	24,432
Deferred Tax Assets | U.S. and foreign
Valuation allowance
Valuation allowance	236,296	234,813
Estimated cumulative amount of earnings from foreign subsidiaries that are permanently reinvested	290,032
Tax credit carryforward | Foreign
Valuation allowance
Valuation allowance	30,067	33,689
Net operating loss (NOL) carry forwards | Foreign
Valuation allowance
Valuation allowance	$ 30,378	$ 54,375