Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 709,848	$ 475,898	$ 421,863
Adjustments to reconcile net income to cash provided by operating activities:
Provision for policy losses and other claims	446,040	452,633	450,410
Depreciation and amortization	129,021	125,927	128,053
Amortization of premiums and accretion of discounts on debt securities, net	26,781	26,994	31,211
Net realized investment (gains) losses	(66,404)	56,487	(11,234)
Share-based compensation	42,474	41,145	37,399
Equity in earnings of affiliates, net	(2,836)	(2,717)	(3,785)
Dividends from equity method investments	5,628	4,909	11,083
Changes in assets and liabilities excluding effects of acquisitions and noncash transactions:
Claims paid, including assets acquired, net of recoveries	(415,321)	(450,756)	(472,047)
Net change in income tax accounts	16,399	42,079	(102,819)
(Increase) decrease in accounts and accrued income receivable	(27,240)	5,264	12,426
Increase in accounts payable and accrued liabilities	45,549	15,303	127,683
Increase in deferred revenue	10,343	2,741	10,238
Other, net	(7,193)	(2,742)	(8,347)
Cash provided by operating activities	913,089	793,165	632,134
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash effect of acquisitions/dispositions	(19,674)	(79,171)	(82,993)
Net (increase) decrease in deposits with banks	(8,307)	3,361	(18,319)
Purchases of debt and equity securities	(2,340,836)	(3,157,893)	(1,970,597)
Proceeds from sales of debt and equity securities	1,331,192	1,501,402	1,163,765
Proceeds from maturities of debt securities	1,006,755	640,558	641,442
Investments in unconsolidated entities	(101,000)	(1,210)	(150)
Net change in other investments	(3,842)	(5,582)	3,913
Advances under secured financing agreements	(8,001,099)	(2,380,878)	0
Collections of secured financings receivable	7,789,951	2,374,329	0
Capital expenditures	(106,979)	(118,170)	(134,206)
Proceeds from sales of property and equipment	647	2,630	9,977
Proceeds from insurance settlement	960	0	0
Cash used for investing activities	(452,232)	(1,220,624)	(387,168)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net change in deposits	(448,752)	715,617	291,088
Borrowings under secured financing agreements	7,991,617	2,380,976	0
Repayments of secured financings payable	(7,789,518)	(2,374,426)	0
Borrowings under unsecured credit agreement	160,000	0	0
Repayments of notes and contracts payable	(165,569)	(5,294)	(5,543)
Net activity related to noncontrolling interests	(1,154)	(745)	(969)
Net (payments) proceeds in connection with share-based compensation	(1,187)	(4,105)	2,732
Purchase of Company shares	(2,066)	(18,801)	0
Payments of cash dividends	(188,440)	(178,487)	(159,284)
Cash (used for) provided by financing activities	(445,069)	514,735	128,024
Effect of exchange rate changes on cash	3,042	(7,373)	8,098
Net increase in cash and cash equivalents	18,830	79,903	381,088
Cash and cash equivalents—Beginning of year	1,467,129	1,387,226	1,006,138
Cash and cash equivalents—End of year	1,485,959	1,467,129	1,387,226
SUPPLEMENTAL INFORMATION:
Interest	46,266	39,183	33,680
Premium taxes	68,276	68,526	66,785
Income taxes, less refunds of $1,604, $7,255 and $52,153	$ 178,743	$ 91,745	$ 126,208