Dividends - Additional Information (Details) (USD $)	3 Months Ended		9 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Nov. 05, 2014 Subsequent Event
Dividends Payable [Line Items]
Paid cash dividends, per share			$ 0.30	$ 0.26
Dividends declared per common share	$ 0.10	$ 0.09	$ 0.30	$ 0.26	$ 0.10
Dividend payable, date declared, day month and year					Nov. 05, 2014
Dividends payable, date to be paid, day, month and year					Dec. 03, 2014
Dividends payable, date of record, day, month and year					Nov. 18, 2014