Employee Benefit Plans (Details)	12 Months Ended
	Dec. 31, 2011
Defined contribution pension plans
Maximum employer matching contribution, U.S. employees (as a percent)	4.00%
Maximum employer discretionary contribution, U.S. employees (as a percent)	2.00%
Maximum employer matching contribution, non-U.S. employees (as a percent)	6.00%
Additional contribution towards insurance and administrative costs, non-U.S. employees (as a percent)	2.00%