Finance Receivables, net Finance Receivables, net (Initial Negative Allowance for Recoveries) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025	Dec. 31, 2024
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses at acquisition	$ (1,252,394)	$ (1,491,563)
Writeoffs, net	1,252,394	1,491,563
Expected recoveries	220,850	291,702
Purchase price	220,850	291,702
Amortized cost	0		$ 0
Negative allowance for expected recoveries	4,637,094		4,688,024
Balance as of end of period	4,637,094	4,308,334	4,688,024	$ 4,140,742
Core
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses at acquisition	(1,190,672)	(1,417,971)
Writeoffs, net	1,190,672	1,417,971
Expected recoveries	202,950	273,893
Purchase price	202,950	273,893
Balance as of end of period	4,344,825	3,986,864	4,383,201	3,809,723
Insolvency
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses at acquisition	(61,722)	(73,592)
Writeoffs, net	61,722	73,592
Expected recoveries	17,900	17,809
Purchase price	17,900	17,809
Balance as of end of period	$ 292,269	$ 321,470	$ 304,823	$ 331,019