Accounting Policies - Accumulated Other Comprehensive Loss by Component, Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,699,607
Other comprehensive income (loss), net of tax	27,622	$ (86,099)
Ending balance	1,676,561
Foreign currency translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(227,349)
Other comprehensive income (loss) before reclassifications	32,211
Amounts reclassified from accumulated other comprehensive income	0
Other comprehensive income (loss), net of tax	32,211
Ending balance	(195,138)
Derivative contracts
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,987)
Other comprehensive income (loss) before reclassifications	(1,885)
Amounts reclassified from accumulated other comprehensive income	(325)
Other comprehensive income (loss), net of tax	(1,560)
Ending balance	(4,547)
Pension and post retirement benefit plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(46,383)
Other comprehensive income (loss) before reclassifications	(3,533)
Amounts reclassified from accumulated other comprehensive income	(504)
Other comprehensive income (loss), net of tax	(3,029)
Ending balance	(49,412)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(276,719)
Other comprehensive income (loss) before reclassifications	26,793
Amounts reclassified from accumulated other comprehensive income	(829)
Other comprehensive income (loss), net of tax	27,622
Ending balance	$ (249,097)