Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Treasury stock, shares of common stock (in shares)	2,064	1,448	2,421
Retirement of treasury shares (in shares)	(2,064)	(1,448)	(2,421)
Interest rate swap, tax	$ (839)	$ 653	$ 194
Exercise and lapse of share-based awards, tax benefit	$ 7,370	$ 7,706	$ 5,524