Employee Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Employee Benefit Plans [Line Items]
Pension expense	$ 5,600,000	$ 4,700,000	$ 6,000,000
Plan costs for defined benefit pension plans	100,000	100,000	100,000
Projected benefit obligation for defined benefit pension plans	3,900,000	1,700,000
Unrealized gains (losses) recorded in other comprehensive income related to the additional minimum pension liability	(796,000)	0	0
Incentive compensation expense	13,200,000	24,700,000	12,500,000
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of employee's gross pay	3.00%
Deferred compensation plan assets	3,000,000	2,800,000
Deferred compensation plan liability	3,000,000	2,800,000
Locations Outside The U.S. and Netherlands [Member]
Employee Benefit Plans [Line Items]
Plan costs for defined contribution plans	3,600,000	2,200,000	1,400,000
Domestic Country [Member]
Employee Benefit Plans [Line Items]
Plan costs for defined contribution plans	$ 1,800,000	$ 1,500,000	$ 1,500,000