Income Taxes (Details 1) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Assets, Gross [Abstract]
Deferred Tax Assets, Allowance for doubtful accounts	$ 662	$ 494
Deferred Tax Assets, Depreciation and amortization	(1,610)	(19,338)
Deferred Tax Assets, Inventory valuation	15,911	17,072
Deferred Tax Assets, Other postretirement/postemployment costs	2,978	17,549
Deferred Tax Assets, Tax loss carryforwards	13,412	13,977
Deferred Tax Assets, Pension	1,663	21,968
Deferred Tax Assets, Accrued compensation	2,975	15,418
Deferred Tax Assets, Goodwill	0	(13,772)
Deferred Tax Assets, Other	4,374	4,398
Deferred Tax Assets	40,365	57,766
Deferred Tax Assets, Valuation allowance	(14,401)	(15,856)
Deferred Tax Assets, Net	25,964	41,910
Deferred Tax Assets, Net, Classification [Abstract]
Deferred Tax Assets, Net, Current	24,825	31,849
Deferred Tax Assets, Net non-current	1,139	10,061
Deferred Tax Assets, Net	25,964	41,910
Deferred Tax Liabilities [Abstract]
Deferred Tax Liabilities, Allowance for doubtful accounts	129	86
Deferred Tax Liabilities, Depreciation and amortization	78,786	59,271
Deferred Tax Liabilities, Inventory valuation	1,843	1,981
Deferred Tax Liabilities, Other postretirement/postemployment costs	(12,774)	(247)
Deferred Tax Liabilities, Tax loss carryforwards	(1,919)	(56)
Deferred Tax Liabilities, Pension	(22,946)	(1,005)
Deferred Tax Liabilities, Accrued compensation	(7,267)	0
Deferred Tax Liabilities, Goodwill	14,545	57
Deferred Tax Liabilities, Swedish tax incentive	4,647	4,255
Deferred Tax Liabilities, Unrealized foreign currency (loss) gain	1,350	1,999
Deferred Tax Liabilities, Other	7,513	5,763
Deferred Tax Liabilities	63,907	72,104
Deferred Tax Liabilities, Classification [Abstract]
Deferred Tax Liabilities, Current	1,543	1,957
Deferred Tax Liabilities, Non-current	62,364	70,147
Deferred Tax Liabilities	$ 63,907	$ 72,104