CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Stockholders' Equity [Abstract]
Pension and other postretirement adjustments, tax	$ 578	$ 438
Amortization of forward starting swaps, tax	$ 351	$ 361
Issuance of common stock from performance share units and exercise of stock options (in shares)	131,757	264,090
Issuance of common stock from exercise of stock options and deferred compensation plans, tax amount	$ 3,061	$ 3,415
Purchase of common stock (in shares)	866,823	369,810