Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Reconciliation of liability for unrecognized tax benefits
Balance at the beginning of the period			$ 33,872
Additions based on current year positions			418
Additions based on prior year positions			3,180
Payments made on account			(262)
Currency translation adjustments			(338)
Balance at the end of the period	$ 36,870		$ 36,870
Effective income tax rate (as a percent)	41.00%	33.50%	39.10%	37.50%