CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Net Income	$ 146,157	$ 128,699	$ 412,384	$ 348,385
Other comprehensive income, before tax:
Foreign currency translation adjustments	0	(53)	142	698
Recognition of previously deferred post-retirement benefit plan costs	1,031	1,290	3,092	3,869
Pension payment timing related charge	0	946	0	946
Pension and other postretirement benefit items	1,031	2,236	3,092	4,815
Unrealized gain on available-for-sale investment during the period	0	54,354	0	54,354
Realized gain on available-for-sale investment during the period	0	0	(20,800)	0
Other comprehensive income (loss), before tax	1,031	56,537	(17,566)	59,867
Income tax effect related to components of other comprehensive income	(265)	(14,626)	4,520	(15,484)
Other comprehensive income (loss), net of tax	766	41,911	(13,046)	44,383
Comprehensive income	146,923	170,610	399,338	392,768
Comprehensive income attributable to redeemable noncontrolling interest	(92)	(419)	(516)	(861)
Total comprehensive income	$ 146,831	$ 170,191	$ 398,822	$ 391,907