Accumulated Other Comprehensive Income (Loss) (AOCI balances) (Details 2) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income, beginning balance	$ 2,452,941
Other Comprehensive Income, Net of Tax	18,282	$ 3,235
Accumulated Other Comprehensive Income, ending balance	2,480,578
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income, beginning balance	236,486
Other comprehensive (loss) income before reclassifications	19,279
Net amount reclassified from accumulated other comprehensive income	(997)
Other Comprehensive Income, Net of Tax	18,282
Accumulated Other Comprehensive Income, ending balance	254,768
Cumulative Foreign Currency Translation Adjustment [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income, beginning balance	(26,998)
Other comprehensive (loss) income before reclassifications	13,668	3,845
Net amount reclassified from accumulated other comprehensive income	0
Other Comprehensive Income, Net of Tax	13,668
Accumulated Other Comprehensive Income, ending balance	(13,330)
Unrealized Gain on Available-for-Sale Securities [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income, beginning balance	92,931
Other comprehensive (loss) income before reclassifications	5,735	206
Net amount reclassified from accumulated other comprehensive income	0	(1,053)
Other Comprehensive Income, Net of Tax	5,735	(847)
Accumulated Other Comprehensive Income, ending balance	98,666
Unrealized Gain on Pensions and Other Postretirement Plans [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income, beginning balance	170,830
Other comprehensive (loss) income before reclassifications	0
Net amount reclassified from accumulated other comprehensive income	(1,022)	237
Other Comprehensive Income, Net of Tax	(1,022)	237
Accumulated Other Comprehensive Income, ending balance	169,808
Cash Flow Hedge [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income, beginning balance	(277)
Other comprehensive (loss) income before reclassifications	(124)
Net amount reclassified from accumulated other comprehensive income	25
Other Comprehensive Income, Net of Tax	(99)	$ 0
Accumulated Other Comprehensive Income, ending balance	$ (376)