Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends (in dollars per share)	$ 0.42	$ 0.52	$ 0.47
Income tax benefit of shares and options issued under stock plans	$ 2,546