Summary of Significant Accounting Policies		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) segment
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | segment						1
Uninsured cash and cash equivalents		$ 7,900,000		$ 7,900,000		$ 186,100,000
Adoption of CECL	[1]			0
Provision for credit losses		139,400,000	$ 15,400,000	494,100,000	$ 29,900,000
CECL Impact on Net Income		118,700,000		240,300,000
CECL Impact on Net Income, Per Diluted Share		6.65		13.32
Restricted Cash and Cash Equivalents [Member]
Summary Of Significant Accounting Policies [Line Items]
Uninsured cash and cash equivalents		379,000,000.0		379,000,000.0		$ 326,700,000
New Consumer Loan Assignments [Member]
Summary Of Significant Accounting Policies [Line Items]
Provision for credit losses		154,200,000	0	312,100,000	0
Loans Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Adoption of CECL	[1]			2,463,600,000
Provision for credit losses		$ 0	$ 0	$ 0	$ 0

[1] Represents the gross-up of Loans receivable and allowance for credit losses on January 1, 2020 upon the adoption of CECL for the present value of the difference between contractual future net cash flows and expected future net cash flows discounted at the effective interest rate.