Supplemental Cash Flow Information - Supplemental Disclosure of Non-cash Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Oct. 01, 2019	Sep. 30, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 12,975
Operating lease liabilities	15,158
Supplemental disclosure of cash activity:
Interest payments	15,954	$ 13,986
Income tax payments	0	121
Tax refunds received	303	1,148
Reconciliation of cash, cash equivalents, and restricted cash:
Cash and cash equivalents	41,277	84,399		$ 106,741
Restricted cash	18,759	12,637		$ 16,053
Total cash, cash equivalents, and restricted cash shown in the statement of cash flows	$ 60,036	$ 97,036
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets			$ 13,900
Operating lease liabilities			$ 16,028