CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Pension and other postretirement adjustments, tax	$ 2,799	$ 309	$ 62	$ 578
Amortization of forward starting swaps, tax	$ 549	$ 195	$ 623	$ 351
Issuance of common stock from performance share units and exercise of stock options (in shares)	67,476	106,122	145,263	131,757
Issuance of common stock from exercise of stock options and deferred compensation plans, tax amount	$ 621	$ 1,865	$ 594	$ 3,061
Purchase of common stock (in shares)			9,600	866,823
Cash dividends declared, per common share outstanding (in dollars per share)	$ 1.08		$ 1.00