Derivative Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative gain (loss)	$ 1,374	$ 34,290	$ (23,842)	$ 23,699