Common Stock - Stock Repurchase Program (Details) - USD ($)	3 Months Ended		22 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Jun. 30, 2015	Nov. 30, 2012
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, remaining amount	$ 54,900,000		$ 54,900,000
Credit Facility
Equity, Class of Treasury Stock [Line Items]
Share repurchase covenant	$ 4,900,000
Share Repurchase Program, November 2012
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount (up to)					$ 25,000,000
Repurchase of common stock during period (in shares)	0	0
Share Repurchase Program, June 2015
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount (up to)				$ 50,000,000
Repurchase of common stock during period (in shares)			0