Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 231,263	$ 179,964
Adjustments to reconcile net income to cash provided by operating activities:
Provision for policy losses and other claims	214,199	213,346
Depreciation and amortization	60,805	60,292
Amortization of premiums and accretion of discounts on debt securities, net	13,451	16,666
Net realized investment losses (gains)	169	(17,764)
Share-based compensation	27,135	24,580
Equity in earnings of affiliates, net	(708)	(3,447)
Dividends from equity method investments	1,774	5,562
Changes in assets and liabilities excluding effects of acquisitions and noncash transactions:
Claims paid, including assets acquired, net of recoveries	(213,538)	(225,849)
Net change in income tax accounts	20,560	104,656
Increase in accounts and accrued income receivable	(36,700)	(18,411)
Decrease in accounts payable and accrued liabilities	(59,871)	(92,662)
(Decrease) increase in deferred revenue	(1,149)	2,468
Other, net	(3,290)	(14,797)
Cash provided by operating activities	254,100	234,604
Cash flows from investing activities:
Net cash effect of acquisitions/dispositions	(73,757)	(3,933)
Net (increase) decrease in deposits with banks	(757)	110
Purchases of debt and equity securities	(1,166,788)	(1,029,861)
Proceeds from sales of debt and equity securities	470,670	499,526
Proceeds from maturities of debt securities	282,754	276,843
Net change in other investments	563	2,105
Advances under secured financing agreements	(580,162)	0
Collections of secured financings receivable	553,632	0
Capital expenditures	(55,720)	(69,553)
Proceeds from sales of property and equipment	1,624	9,013
Cash used for investing activities	(567,941)	(315,750)
Cash flows from financing activities:
Net change in deposits	227,594	318,318
Borrowings under secured financing agreements	579,871	0
Repayments of secured financings payable	(553,513)	0
Repayments of notes and contracts payable	(2,681)	(2,660)
Net activity related to noncontrolling interests	(920)	(879)
Net payments in connection with share-based compensation plans	(11,229)	(2,167)
Cash dividends	(84,717)	(75,099)
Cash provided by financing activities	154,405	237,513
Effect of exchange rate changes on cash	(1,280)	4,259
Net (decrease) increase in cash and cash equivalents	(160,716)	160,626
Cash and cash equivalents—Beginning of period	1,387,226	1,006,138
Cash and cash equivalents—End of period	1,226,510	1,166,764
Supplemental information:
Interest	18,591	16,811
Premium taxes	42,840	41,652
Income taxes, less refunds of $18 and $51,904	$ 42,456	$ (16,696)