Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Common Stock, Shares, Outstanding	44,141,973		44,141,973			45,641,238
Stockholders' Equity Attributable to Parent	$ 2,885,408	$ 2,817,201	$ 2,885,408	$ 2,817,201	$ 2,854,914	$ 2,886,701	$ 2,871,185	$ 3,018,449
Held In Rabbi Trust At Cost [Member]
Stockholders' Equity Attributable to Parent	$ (3,335)	$ (3,239)	$ (3,335)	$ (3,239)	(3,289)	(3,227)	(3,196)	(3,146)
Retained Earnings
Cash dividends declared per common share (in dollars per share)	$ 0.55	$ 0.51	$ 1.65	$ 1.53
Stockholders' Equity Attributable to Parent	$ 1,046,266	$ 882,503	$ 1,046,266	$ 882,503	1,009,735	934,442	833,857	766,716
Deferred Compensation, Share-based Payments [Member]
Stockholders' Equity Attributable to Parent	3,335	3,239	3,335	3,239	3,289	3,227	3,196	3,146
AOCI Attributable to Parent [Member]
Stockholders' Equity Attributable to Parent	(160,746)	(179,069)	(160,746)	(179,069)	(152,935)	(163,084)	(109,464)	2,183
Common Stock [Member]
Stockholders' Equity Attributable to Parent	440	454	440	454	440	455	459	472
Additional Paid-in Capital [Member]
Stockholders' Equity Attributable to Parent	$ 1,999,448	$ 2,113,313	$ 1,999,448	$ 2,113,313	$ 1,997,674	$ 2,114,888	$ 2,146,333	$ 2,249,078
Common Class A [Member]
Common Stock, Shares, Outstanding	44,141,973	45,634,626	44,141,973	45,634,626	44,130,901	45,641,238	46,069,761	47,349,778