Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Unrealized gain (loss) on derivatives, tax benefit	$ 5,735	$ (2,713)
Cash dividends declared per share		$ 0.73	$ 0.84
Repurchase of treasury stock, Shares			2,413,803
Accumulated Other Comprehensive Income (Loss) [Member]
Unrealized gain (loss) on derivatives, tax benefit	$ 5,735	$ (2,713)	$ (6,115)