Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 234,458	$ 63,846
Adjustments to reconcile net income to cash provided by operating activities:
Provision for policy losses and other claims	140,447	117,477
Depreciation and amortization	38,298	31,449
Amortization of premiums and accretion of discounts on debt securities, net	11,251	9,952
Net realized investment (gains) losses	(66,833)	64,762
Share-based compensation	31,203	25,903
Equity in (earnings) losses of equity method investments, net	(1,088)	228
Dividends from equity method investments	2,795	1,402
Changes in assets and liabilities excluding effects of acquisitions and noncash transactions:
Claims paid, including assets acquired, net of recoveries	(118,208)	(108,538)
Net change in income tax accounts	64,092	5,181
Increase in accounts and accrued income receivable	(7,825)	(45,747)
Decrease in accounts payable and accrued liabilities	(81,789)	(149,960)
Decrease in deferred revenue	(19,310)	(15,753)
Other, net	(3,582)	23,952
Cash provided by operating activities	223,909	24,154
Cash flows from investing activities:
Net cash effect of acquisitions/dispositions	0	(386,231)
Net (increase) decrease in deposits with banks	(295)	2,095
Purchases of debt and equity securities	(1,411,674)	(588,327)
Proceeds from sales of debt and equity securities	259,503	211,370
Proceeds from maturities of debt securities	432,159	320,523
Investments in unconsolidated entities	(14,928)	(44,795)
Net change in other investments	(19,414)	298
Advances under secured financing agreements	(6,282,240)	(3,028,490)
Collections of secured financings receivable	6,284,739	2,835,789
Capital expenditures	(28,582)	(29,213)
Proceeds from sales of property and equipment	688	14,141
Proceeds from insurance settlement	754	0
Cash used for investing activities	(779,290)	(692,840)
Cash flows from financing activities:
Net change in deposits	1,303,579	93,916
Borrowings under secured financing agreements	5,234,634	2,998,687
Repayments of secured financings payable	(5,105,259)	(2,835,442)
Borrowings under unsecured credit facility	0	120,000
Repayments of notes and contracts payable	(1,599)	(1,338)
Net activity related to noncontrolling interests	(2,095)	(1,328)
Net payments in connection with share-based compensation	(8,378)	(14,378)
Repurchases of Company shares	(64,786)	(65,785)
Payments of cash dividends	(50,985)	(49,702)
Cash provided by financing activities	1,305,111	244,630
Effect of exchange rate changes on cash	828	(11,918)
Net increase (decrease) in cash and cash equivalents	750,558	(435,974)
Cash and cash equivalents—Beginning of period	1,275,466	1,485,959
Cash and cash equivalents—End of period	2,026,024	1,049,985
Supplemental information:
Interest	10,803	9,462
Premium taxes	29,400	25,049
Income taxes, less refunds of $114 and $71	$ 7,470	$ 3,239