Stockholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax	[1]			$ (21,272)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				17,838
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				(344)
Other Comprehensive Income (Loss), Net of Tax		$ 5,609	$ 700	17,494	$ 2,532
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent				238
Accumulated Other Comprehensive Income (Loss), Net of Tax		(3,778)		(3,778)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax				(21,272)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				16,747
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				0
Other Comprehensive Income (Loss), Net of Tax				16,747
Accumulated Other Comprehensive Income (Loss), Net of Tax		(4,525)		(4,525)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax				0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax				1,329
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax				(344)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent				985
Accumulated Other Comprehensive Income (Loss), Net of Tax		985		985
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax				0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				(238)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax				0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent				(238)
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ (238)		$ (238)

[1] December 31, 2016 balances were derived from audited consolidated financial statements.