Pensions (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
U.S. Plans
Change in Projected Benefit Obligations
Projected benefit obligation at beginning of year	$ 116,620,000	$ 106,127,000
Service cost	1,165,000	1,059,000	1,022,000
Interest cost	4,423,000	4,796,000	4,942,000
Actuarial (gain) loss	(14,471,000)	12,083,000
Benefits paid	(5,428,000)	(3,343,000)
Settlement		(4,102,000)
Projected benefit obligation at end of year	102,309,000	116,620,000	106,127,000
Change in Plan Assets
Fair value of plan assets at beginning of year	88,184,000	82,970,000
Actual return on plan assets	14,186,000	10,577,000
Employer contributions	2,842,000	2,082,000
Benefits paid	(5,428,000)	(3,343,000)
Settlement		(4,102,000)
Fair value of plan assets at end of year	99,784,000	88,184,000	82,970,000
Funded status of plan assets	(2,525,000)	(28,436,000)
Amounts recognized in the Balance Sheets:
Noncurrent asset	2,470,000
Current liability - Accrued benefit cost	(82,000)	(82,000)
Noncurrent liability - Accrued benefit cost	(4,913,000)	(28,354,000)
Net amount recognized	(2,525,000)	(28,436,000)
Amounts recognized in Accumulated Other Comprehensive Income consist of:
Accumulated prior service cost	89,000	164,000
Accumulated net actuarial loss	20,752,000	46,267,000
Net amount recognized, before tax effect	20,841,000	46,431,000
Accumulated benefit obligation at year end	50,200,000	111,600,000
Weighted-average assumptions used to determine benefit obligations at period end:
Discount rate (as a percent)	4.88%	3.92%
Rate of increase in compensation levels (as a percent)	3.50%	4.00%
European Plans
Change in Projected Benefit Obligations
Projected benefit obligation at beginning of year	42,417,000	33,469,000
Service cost	314,000	148,000	155,000
Interest cost	1,511,000	1,640,000	1,947,000
Employee contributions	103,000	119,000
Actuarial (gain) loss	1,178,000	5,203,000
Benefits paid	(1,550,000)	(1,254,000)
Settlement	(1,249,000)
Other	(1,689,000)	1,689,000
Foreign currency exchange rate changes	1,332,000	1,403,000
Projected benefit obligation at end of year	42,367,000	42,417,000	33,469,000
Change in Plan Assets
Fair value of plan assets at beginning of year	28,177,000	24,414,000
Actual return on plan assets	1,395,000	2,053,000
Employer contributions	1,875,000	1,831,000
Employee contributions	103,000	119,000
Benefits paid	(1,550,000)	(1,254,000)
Settlement	(1,249,000)
Foreign currency exchange rate changes	835,000	1,014,000
Fair value of plan assets at end of year	29,586,000	28,177,000	24,414,000
Funded status of plan assets	(12,781,000)	(14,240,000)
Amounts recognized in the Balance Sheets:
Noncurrent asset	603,000	1,013,000
Current liability - Accrued benefit cost	(561,000)	(590,000)
Noncurrent liability - Accrued benefit cost	(12,823,000)	(14,663,000)
Net amount recognized	(12,781,000)	(14,240,000)
Amounts recognized in Accumulated Other Comprehensive Income consist of:
Accumulated net actuarial loss	7,022,000	6,167,000
Net amount recognized, before tax effect	7,022,000	6,167,000
Accumulated benefit obligation at year end	$ 40,500,000	$ 40,500,000
Weighted-average assumptions used to determine benefit obligations at period end:
Discount rate (as a percent)	3.92%	3.95%
Rate of increase in compensation levels (as a percent)	3.50%	3.50%