Shareholders' Equity Amounts recognized from accumulated other comprehensive income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	$ 109	$ 539	$ 1,679
Cross Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(1,022)	2,212	(1,416)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	913	(2,751)	(263)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(52)	310	536
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	(861)	2,441	(273)
Amortization of actuarial (gains) losses and plan amendments and prior service cost	15,467	18,756	20,137
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax, Attributable to Parent	3,323	4,390	5,264
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	$ 12,144	$ 14,366	$ 14,873