Accumulated Other Comprehensive Loss - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenue		$ 1,028,417	$ 891,898	$ 837,492	$ 796,268	$ 831,343	$ 790,125	$ 788,573	$ 795,084	$ 3,554,075	$ 3,205,125	$ 3,211,522
Selling, general and administrative										(963,323)	(1,003,989)	(1,002,935)
Interest expense										(105,753)	(110,910)	(115,381)
Loss on extinguishment of debt	$ (37,000)									(36,987)	(6,623)	(7,964)
Tax provision		813	(554)	(17,016)	10,030	(344)	24,895	(3,724)	(7,820)	(6,727)	13,007	(6,416)
Net (loss) income		$ 18,879	$ 11,389	$ (3,329)	$ (208,483)	$ 176,696	$ (3,125)	$ 23,697	$ (2,659)	(181,544)	194,609	241,811
Amounts Reclassified from AOCI | Cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenue										(161)	72	11
Cost of sales										11	104	51
Interest expense										0	0	(1,183)
Loss on extinguishment of debt										0	0	(1,267)
Total before tax										(150)	176	(2,388)
Tax provision										(37)	44	(941)
Net (loss) income										(113)	132	(1,447)
Amounts Reclassified from AOCI | Available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenue										10,124	1,079	3,244
Selling, general and administrative										(231)	0	0
Total before tax										10,355	1,079	3,244
Tax provision										2,589	270	821
Net (loss) income										7,766	809	2,423
Amounts Reclassified from AOCI | Pension and postretirement benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax										(50,508)	(37,785)	(86,674)
Tax provision										(11,930)	(9,497)	(21,675)
Net (loss) income										(38,578)	(28,288)	(64,999)
Amounts Reclassified from AOCI | Transition asset
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pension and Postretirement Benefit Plans										4	6	7
Amounts Reclassified from AOCI | Prior service costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pension and Postretirement Benefit Plans										(558)	(504)	(173)
Amounts Reclassified from AOCI | Actuarial losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pension and Postretirement Benefit Plans										(43,530)	(34,509)	(41,610)
Amounts Reclassified from AOCI | Settlement
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pension and Postretirement Benefit Plans										$ (6,424)	$ (2,778)	$ (44,898)