Significant Accounting Polices - Narrative (Details) - USD ($) $ in Thousands		9 Months Ended
	Apr. 30, 2014	Sep. 30, 2016	Sep. 30, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax expense and other income		$ 120,987	$ 109,865
Consolidated loan rebate fee		1.05%
Additional Tax Positions
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (Decrease) in tax receivable and income tax payable	$ 120,000
Income tax expense and other income	$ 9,000