Earnings Per Share Earnings Per Share - Additional Information (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended
	Dec. 09, 2013	Sep. 30, 2014	Dec. 31, 2013	Dec. 09, 2013
Class of Stock [Line Items]
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Shares issued, price per share				$ 44.94
Proceeds from issuance of common stock, net of discounts and expenses	$ 314,400
Common Stock [Member]
Class of Stock [Line Items]
Issuance of common stock, shares	7,000,000
Common stock, par value (in dollars per share)				$ 0.01
Additional Paid-in-Capital [Member]
Class of Stock [Line Items]
Proceeds from issuance of common stock, net of discounts and expenses	314,300
Common Stock [Member]
Class of Stock [Line Items]
Proceeds from issuance of common stock, net of discounts and expenses	$ 70