Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Allowance for doubtful accounts	$ 5,099	$ 9,979
Deferred and other compensation	13,956	10,636
Capital investments	3,795	3,790
Debt, capitalized fees, and other interest	329	2,291
Pension and other post-employment benefits	37,569	51,231
Operating lease liability	9,726	7,539
Reserve for facility exit costs	5,070	7,053
Net operating loss and credit carryforwards	26,522	28,611
Fixed assets and capitalized software	0	420
Non-compete and other agreements	40,335	46,213
Goodwill and other intangible assets	0	8,335
Other, net	6,435	8,566
Total deferred tax assets	148,836	184,664
Net deferred tax assets	127,498	160,357
Deferred tax liabilities
Deferred revenue	(21,033)	(46,501)
Goodwill and other intangible assets	(6,764)	0
Deferred costs	(2,254)	(3,003)
Investment in subsidiaries	(4,828)	(5,466)
Operating lease right-of-use assets	(7,572)	(9,362)
Fixed assets and capitalized software	(2,466)	0
Other, net	(2,814)	(3,434)
Total deferred tax (liabilities)	(47,731)	(67,766)
Net deferred tax asset	$ 79,767	$ 92,591