Stockholders' Equity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Jan. 31, 2016
Equity [Abstract]
Share repurchase program, authorized amount (in shares)			$ 60,000,000.0
Common stock repurchased and retired (in shares)	1,366,266
Stock repurchased and retired during period, value	$ 19,467,000
Average share price (in dollars per share)	$ 14.27
Available for repurchase of shares		$ 20,500,000