Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenue		$ 936,947	$ 869,541	$ 880,891	$ 890,681	$ 983,913	$ 941,644	$ 958,450	$ 937,497	$ 3,578,060		$ 3,821,504		$ 3,791,335
Interest expense										(87,583)		(90,888)		(109,268)
Tax provision (benefit)		44,204	42,676	52,351	50,547	33,134	25,310	46,335	8,036	189,778		112,815		77,967
Net income		90,873	$ 93,876	$ 156,363	85,206	67,122	$ 136,882	$ 98,859	49,267	426,318		352,130		161,210
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at					(846,156)				(574,556)	(846,156)		(574,556)		(681,213)
Other comprehensive income (loss) before reclassifications	[1]									(73,459)		(297,246)		75,387
Amounts reclassified from accumulated other comprehensive income (loss)	[1],[3]									30,980	[2]	25,646	[2]	31,270
Other comprehensive (loss) income										(42,479)		(271,600)		106,657
Balance at		(888,635)				(846,156)				(888,635)		(846,156)		(574,556)
Cash flow hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at					(4,689)				(6,380)	(4,689)		(6,380)		(7,777)
Other comprehensive income (loss) before reclassifications	[1]									546		1,146		(147)
Amounts reclassified from accumulated other comprehensive income (loss)	[1],[3]									231	[2]	545	[2]	1,544
Other comprehensive (loss) income										777		1,691		1,397
Balance at		(3,912)				(4,689)				(3,912)		(4,689)		(6,380)
Available-for-sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at					2,966				(1,769)	2,966		(1,769)		4,513
Other comprehensive income (loss) before reclassifications	[1]									(1,715)		4,010		(7,000)
Amounts reclassified from accumulated other comprehensive income (loss)	[1],[3]									(715)	[2]	725	[2]	718
Other comprehensive (loss) income										(2,430)		4,735		(6,282)
Balance at		536				2,966				536		2,966		(1,769)
Pension and postretirement benefit plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at					(786,079)				(601,421)	(786,079)		(601,421)		(759,199)
Other comprehensive income (loss) before reclassifications	[1]									19,146		(212,818)		122,023
Amounts reclassified from accumulated other comprehensive income (loss)	[1],[3]									28,165	[2]	28,160	[2]	35,755
Other comprehensive (loss) income										47,311		(184,658)		157,778
Balance at		(738,768)				(786,079)				(738,768)		(786,079)		(601,421)
Foreign currency adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at					$ (58,354)				$ 35,014	(58,354)		35,014		81,250
Other comprehensive income (loss) before reclassifications	[1]									(91,436)		(89,584)		(39,489)
Amounts reclassified from accumulated other comprehensive income (loss)	[1],[3]									3,299	[2]	(3,784)	[2]	(6,747)
Other comprehensive (loss) income										(88,137)		(93,368)		(46,236)
Balance at		$ (146,491)				$ (58,354)				(146,491)		(58,354)		35,014
Amounts Reclassified from AOCI | Cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenue										1,082		1,276		(835)
Cost of sales										551		(140)		332
Interest expense										(2,028)		(2,028)		(2,028)
Total before tax										(395)		(892)		(2,531)
Tax provision (benefit)										(164)		(347)		(987)
Net income										(231)		(545)		(1,544)
Amounts Reclassified from AOCI | Available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax provision (benefit)										419		(424)		(422)
Net income										715		(725)		(718)
Interest income										1,134		(1,149)		(1,140)
Amounts Reclassified from AOCI | Pension and postretirement benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax										(44,131)		(43,803)		(54,983)
Tax provision (benefit)										(15,966)		(15,643)		(19,228)
Net income										(28,165)		(28,160)		(35,755)
Transition asset										9		10		9
Prior service costs										(171)		(111)		(620)
Actuarial losses										$ (43,969)		$ (43,702)		$ (54,372)

[1] Amounts are net of tax. Amounts in parentheses indicate debits to AOCI.

[2] Foreign currency item amount represents the recognition of deferred translation upon the sale of certain businesses.

[3] See table above for additional details of these reclassifications.