Long-Term Debt - Narrative (Details) (USD $)	6 Months Ended						1 Months Ended	6 Months Ended				1 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Revolving Credit Facility 2011 Revolving Credit Facility		Sep. 30, 2013 Revolving Credit Facility 2011 Revolving Credit Facility		Apr. 30, 2014 Revolving Credit Facility 2011 Revolving Credit Facility Subsequent Event	Mar. 31, 2014 Revolving Credit Facility 2011 Revolving Credit Facility Eurodollar	Mar. 31, 2014 Revolving Credit Facility 2011 Revolving Credit Facility Eurodollar Minimum	Mar. 31, 2014 Revolving Credit Facility 2011 Revolving Credit Facility Eurodollar Maximum	Apr. 30, 2014 Revolving Credit Facility Restatement Agreement Subsequent Event	Apr. 30, 2014 Revolving Credit Facility Restatement Agreement Eurodollar Subsequent Event	Apr. 30, 2014 Revolving Credit Facility Restatement Agreement Eurodollar Minimum Subsequent Event	Apr. 30, 2014 Revolving Credit Facility Restatement Agreement Eurodollar Maximum Subsequent Event
Line of Credit Facility
Outstanding credit facility			$ 855,000,000
Maximum borrowing capacity											1,550,000,000.00
Credit facility variable rate								Eurodollar				Eurodollar
Credit facility basis spread on variable rate									2.00%	2.50%			1.75%	2.00%
Commitment fee percentage									0.50%	1.00%			0.30%	0.40%
Market adjustable interest rate (per annum)			2.90%	[1]	3.00%	[1]
Proceeds from credit facility	$ 340,000,000	$ 310,000,000					$ 30,000,000

[1] After the impact of our interest rate swaps.