Accumulated Other Comprehensive Income (Changes) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax
Balances, beginning of period	$ 188,561	$ (103,660)
Other comprehensive income (loss) before reclassifications	11,545	19,165
Reclassifications into earnings	8,633	7,137
Other comprehensive income, net of tax	20,178	26,302
Balances, end of period	214,893	(46,338)
Cash flow hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax
Balances, beginning of period	(406)	(1,485)
Other comprehensive income (loss) before reclassifications	43	216
Reclassifications into earnings	443	360
Other comprehensive income, net of tax	486	576
Balances, end of period	80	(909)
Available for sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax
Balances, beginning of period	1,597	120
Other comprehensive income (loss) before reclassifications	(4,010)	516
Reclassifications into earnings	18	69
Other comprehensive income, net of tax	(3,992)	585
Balances, end of period	(2,395)	705
Pension and postretirement benefit plans
Accumulated Other Comprehensive Income (Loss), Net of Tax
Balances, beginning of period	(748,800)	(787,813)
Other comprehensive income (loss) before reclassifications	0	(1,482)
Reclassifications into earnings	8,172	6,708
Other comprehensive income, net of tax	8,172	5,226
Balances, end of period	(740,628)	(782,587)
Foreign currency adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax
Balances, beginning of period	(44,564)	(150,955)
Other comprehensive income (loss) before reclassifications	15,512	19,915
Reclassifications into earnings	0	0
Other comprehensive income, net of tax	15,512	19,915
Balances, end of period	(29,052)	(131,040)
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax
Balances, beginning of period	(792,173)	(940,133)
Other comprehensive income, net of tax	20,178	26,302
Balances, end of period	$ (771,995)	$ (913,831)