Stock Repurchase Program (Details) - USD ($)	1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2015	Nov. 30, 2012
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock, value			$ 7,260,000
Stock repurchase program, remaining amount	$ 57,300,000	$ 57,300,000	$ 57,300,000
Share Repurchase Program, November 2012 [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount				$ 25,000,000
Repurchase of common stock, shares		367,129	547,319
Repurchase of common stock, value		$ 4,600,000	$ 7,300,000
Repurchase of common stock, average price per share (in dollars per share)		$ 12.55	$ 13.26
Share Repurchase Program, June 2015 [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount	$ 50,000,000	$ 50,000,000	$ 50,000,000
Repurchase of common stock, shares	0