Retirement Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Contribution Plan [Member]
Defined Contribution Plans Disclosure [Abstract]
Percentage of matching contributions under defined contribution plan	4.00%
Total expense for defined contribution plans	$ 6,700	$ 5,400	$ 5,000
Pension Plans, Defined Benefit [Member]
Benefit obligation [Roll Forward]
Benefit obligation at beginning of year	46,359	55,396
Service cost	2,091	2,692	2,523
Interest cost	1,669	1,803	2,390
Foreign currency exchange rate changes	(2,306)	(2,379)
Benefits paid	(8,280)	(10,708)
Actuarial loss (gain)	1,906	(1,173)
Curtailment gain	0	(121)
Other	252	849
Benefit obligation at end of year	41,691	46,359	55,396
Change in fair value of plan assets [Roll Forward]
Plan assets at beginning of year	36,236	39,520
Company contributions	6,947	10,204
Foreign currency exchange rate changes	(3,714)	(2,859)
Benefits paid	(8,280)	(10,708)
Actual gain on plan assets	4,952	79
Plan assets at end of year	36,141	36,236	39,520
Funded status	(5,550)	(10,123)
Accumulated benefit obligation	40,743	45,217
Amounts recognized in Consolidated Balance Sheets [Abstract]
Accrued employee and retiree benefits	(14,510)	(14,129)
Other accrued expenses	(765)	(5,927)
Other assets	9,725	9,933
Net liability	(5,550)	(10,123)
Components of annual benefit cost [Abstract]
Service cost	2,091	2,692	2,523
Interest cost	1,669	1,803	2,390
Expected return on plan assets	(1,141)	(1,210)	(1,791)
Amortization of prior service cost	0	0	171
Recognized actuarial loss (gain)	193	228	(305)
Settlement expense	543	1,119	1,467
Curtailment gain	0	(104)	(754)
Defined benefit expense	$ 3,355	$ 4,528	3,701
Weighted average liability assumptions [Abstract]
Discount rate	3.48%	3.94%
Expected return on plan assets	2.85%	3.40%
Rate of compensation increase	0.43%	0.35%
Weighted average cost assumption [Abstract]
Discount rate	3.94%	3.70%
Expected return on plan assets	3.40%	3.32%
Rate of compensation increase	0.35%	0.37%
Amounts recognized in Accumulated Other Comprehensive Income [Abstract]
Unrecognized net actuarial loss	$ 3,384	$ 5,725
Other Comprehensive Income (Loss), Pension Adjustment, Net of Tax [Abstract]
Net actuarial gain (loss) arising during the period	1,312	(140)	(387)
Amortization of actuarial loss, included in defined benefit expense	544	917	1,252
Amortization of prior service cost, included in defined benefit expense	0	0	733
Pension adjustment, net of tax	1,856	777	$ 1,598
Estimated Future Benefit Payments [Abstract]
2017	2,200
2018	3,300
2019	2,200
2020	1,700
2021	2,400
2022 through 2026	18,400
Estimated future employer contributions for next fiscal year	1,000
Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Expected amortization of actuarial loss in next fiscal year	(100)
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	36,141	36,236
Pension Plans, Defined Benefit [Member] | Level 1 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	6,832	6,818
Pension Plans, Defined Benefit [Member] | Level 2 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	29,309	29,418
Pension Plans, Defined Benefit [Member] | Level 3 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	0	0
Pension Plans, Defined Benefit [Member] | Private Equity Funds, Domestic [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	5,830	6,064
Pension Plans, Defined Benefit [Member] | Private Equity Funds, Domestic [Member] | Level 1 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	5,830	6,064
Pension Plans, Defined Benefit [Member] | Private Equity Funds, Domestic [Member] | Level 2 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	0	0
Pension Plans, Defined Benefit [Member] | Private Equity Funds, Domestic [Member] | Level 3 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	0	0
Pension Plans, Defined Benefit [Member] | Private Equity Funds, Foreign [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	254	179
Pension Plans, Defined Benefit [Member] | Private Equity Funds, Foreign [Member] | Level 1 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	106	3
Pension Plans, Defined Benefit [Member] | Private Equity Funds, Foreign [Member] | Level 2 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	148	176
Pension Plans, Defined Benefit [Member] | Private Equity Funds, Foreign [Member] | Level 3 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	0	0
Pension Plans, Defined Benefit [Member] | Fixed Income Funds [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	23,156	22,374
Pension Plans, Defined Benefit [Member] | Fixed Income Funds [Member] | Level 1 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	851	711
Pension Plans, Defined Benefit [Member] | Fixed Income Funds [Member] | Level 2 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	22,305	21,663
Pension Plans, Defined Benefit [Member] | Fixed Income Funds [Member] | Level 3 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	0	0
Pension Plans, Defined Benefit [Member] | Other Investments [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	6,901	7,619
Pension Plans, Defined Benefit [Member] | Other Investments [Member] | Level 1 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	45	40
Pension Plans, Defined Benefit [Member] | Other Investments [Member] | Level 2 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	6,856	7,579
Pension Plans, Defined Benefit [Member] | Other Investments [Member] | Level 3 [Member]
Pension Plan Assets by Asset Category [Abstract]
Total assets at fair value	$ 0	$ 0