Derivative Instruments - Narrative (Details) - USD ($)	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gain (loss) from components excluded from assessment of cash flow hedge effectiveness, net	$ 0	$ 0
Gain (loss) on discontinuation of cash flow hedge due to forecasted transaction probable of not occurring, net	0	$ 0
Cash flow hedge gain (loss) to be reclassified within twelve months	$ 2,600,000