Stockholders' Equity - Repurchase Activities (Details) - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2013	Dec. 31, 2016	Dec. 31, 2015	May 19, 2015	May 18, 2015
Equity [Abstract]
Common stock, shares authorized (in shares)		100,000,000	100,000,000	100,000,000	50,000,000
Authorized increase to stock repurchase plan	$ 30,000,000
Common stock available for future share repurchases, amount	$ 2,300,000	$ 2,600,000	$ 11,500,000
Number of shares repurchased (in shares)		237,869	302,366
Average price per share (in dollars per share)		$ 37.76	$ 30.35
Total repurchase costs (in millions)		$ 8,900,000	$ 9,200,000