Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Statement of Stockholders' Equity [Abstract]
Excess tax benefit from stock-based compensation		$ 39
Gain (loss) on reissuance of treasury stock	$ 5,004	$ (50)
Shares repurchased (shares)		1,671,923
Cash dividends declared per share	$ 0.16	$ 0.1