Consolidated Statements of Equity (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Tax effect of adoption of new accounting standard		$ (76)	$ 3,492
Income Tax Effects Allocated Directly to Equity, Employee Stock Options	$ 0	$ 0	$ 267
Number Of Common Shares Issued For Cash	150	723	127
Dividends declared, per common share (in dollars per share)	$ 0.70	$ 0.685	$ 0.665