Subsequent Event - Additional Information (Details) - USD ($)	Nov. 03, 2015	Sep. 30, 2015	Dec. 31, 2014
Subsequent Event [Line Items]
Common stock par value		$ 0.666	$ 0.666
Subsequent Event
Subsequent Event [Line Items]
Stock repurchase program expiration date	Dec. 31, 2019
Subsequent Event | Maximum
Subsequent Event [Line Items]
Authorized amount of common stock under stock repurchase program	$ 100,000,000
Subsequent Event | Stock Repurchase Program
Subsequent Event [Line Items]
Common stock par value	$ 0.66