(Accumulated Other Comprehensive Income (Loss) Rollforward) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Accumulated Other Comprehensive Income (Loss), Tax [Roll Forward]
Balance at December 31, 2016, tax	$ 234,879
Amounts reclassified from accumulated other comprehensive loss, tax	(4,611)
Current-period other comprehensive income (loss) activity, tax	12,481
Balance at September 30, 2017, tax	242,749
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at December 31, 2016, net of tax	(435,991)
Amounts reclassified from accumulated other comprehensive loss, net of tax	6,481
Current-period other comprehensive income (loss) activity, net of tax	2,868
Balance at September 30, 2017, net of tax	(426,642)
Cumulative translation adjustment
Accumulated Other Comprehensive Income (Loss), Before Tax [Roll Forward]
Balance at December 31, 2016, before tax	(78,059)
Amounts reclassified from accumulated other comprehensive loss, before tax	0
Current-period other comprehensive income (loss) activity, before tax	34,047
Balance at September 30, 2017, before tax	(44,012)
Foreign exchange contracts
Accumulated Other Comprehensive Income (Loss), Before Tax [Roll Forward]
Balance at December 31, 2016, before tax	13,772
Amounts reclassified from accumulated other comprehensive loss, before tax	(3,348)
Current-period other comprehensive income (loss) activity, before tax	(43,660)
Balance at September 30, 2017, before tax	(33,236)
Defined benefit plans
Accumulated Other Comprehensive Income (Loss), Before Tax [Roll Forward]
Balance at December 31, 2016, before tax	(606,583)
Amounts reclassified from accumulated other comprehensive loss, before tax	14,440
Current-period other comprehensive income (loss) activity, before tax	0
Balance at September 30, 2017, before tax	$ (592,143)