Stock Repurchases - Additional Information (Details) (USD $)	3 Months Ended	32 Months Ended
	Mar. 31, 2015	Mar. 31, 2015	Aug. 31, 2012	Nov. 30, 2014
Equity, Class of Treasury Stock [Line Items]
Total number of shares repurchased	0
Stock repurchases program, remaining authorized repurchase amount	$ 54,900,000	$ 54,900,000
August 2012 Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchases program, authorized amount			50,000,000
Stock repurchases program, amount repurchased		45,100,000
November 2014 Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchases program, authorized amount				$ 50,000,000