Retirement and Benefit Plans (Details) (USD $)	3 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2012 Times Participants	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Death Benefit Only Plan, Benefit Payment as Multiplier of Final Earnings, Current Employee		3
Maximum percentage of matching contribution for total compensation		3.00%
Percentage quarterly contributions of qualified wages	4.00%	1.00%
Contribution expense		$ 3,620,000	$ 5,599,000	$ 7,153,000
Defined Benefit Plan, Number of Participants Unaffected by Plan Conversion		3
Accumulated other comprehensive income (loss)		5,613,000	4,781,000
Accumulated other comprehensive income, net change		832,000
Net periodic benefit costs		744,000
Defined Benefit Plan, Death Benefit Only Plan, Benefit Payment as Multiplier of Final Earnings, Post-Employment		1
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Company matching employee contributions		66.70%
Supplemental Executive Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate, interest credited	6.00%	0.00%
Projected benefit obligation, unfunded plan		27,851,000	27,879,000
Accumulated benefit obligation		27,851,000	27,879,000
Assumption, future salary increase rate		4.00%
Assumed discount rate		4.05%	4.40%
Retirement age		65
Interest cost		187,000	904,000	1,535,000
Benefit payments		398,000	410,000	1,592,000
Net periodic benefit costs		370,000	1,765,000	2,176,000
Death Benefit Only Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation expense		509,000	536,000	399,000
Service cost and accrual adjustments		412,000	449,000	235,000
Netherlands Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Retirement age		65
European Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Amounts recognized in other comprehensive income (loss)		$ 105,000	$ 215,000	$ (23,000)