Fair Value Measurements - Notes Receivable (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2017	Mar. 31, 2017	Mar. 31, 2016	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes receivable, related party	$ 75,100	$ 75,100
Principal collections on notes receivable	(7,300)	(15,051)	$ 0
Discount	4,800	4,800		$ 6,700
Notes receivable, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Recorded in Consolidated Balance Sheet	70,297	70,297		83,065
Maximum Exposure to Loss	70,297	70,297		83,065
Prepaid expenses and other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Recorded in Consolidated Balance Sheet	562	562		1,209
Maximum Exposure to Loss	0	0		0
Accounts payable, accrued expenses and other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability Recorded in Consolidated Balance Sheet	(584)	(584)		(1,258)
Maximum Exposure to Loss	0	0		0
Disposal Group | Grupo Finmart | Accounts payable, accrued expenses and other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maximum Exposure to Loss	$ 11,800	$ 11,800		$ 25,300