Consolidated Balance Sheet Consolidated Balance Sheet - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets [Abstract]
Fixed maturity securities	$ 13,422,979	$ 13,190,668
Loans receivable	611,378	669,200
Equity securities available for sale	753,278	299,999
Investment funds	1,238,558	1,198,146
Loans receivable	103,650	106,798
Real estate	1,237,738	1,184,981
Total investments	17,367,581	16,649,792
Cash and cash equivalents	608,393	795,285
Premiums and fees receivable	1,766,478	1,701,854
Due from reinsurers	1,640,190	1,743,980
Prepaid reinsurance premiums	451,886	413,140
Trading account receivables from brokers and clearing organizations	29,131	484,593
Deferred policy acquisition costs	544,914	537,890
Property, furniture and equipment	356,908	349,432
Goodwill	144,513	144,513
Accrued investment income	135,439	127,047
Other assets	501,981	402,550
Total assets	23,547,414	23,350,076
Liabilities:
Reserves for losses and loss expenses	11,224,324	11,197,195
Unearned premiums	3,402,892	3,283,300
Due to reinsurers	218,040	213,128
Trading account securities sold but not yet purchased	51,348	51,179
Deferred Tax Liabilities, Net, Current	169,959	119,597
Other liabilities	775,039	916,318
Subordinated debentures	727,777	727,630
Senior notes and other debt	1,759,494	1,760,595
Total liabilities	18,328,873	18,268,942
Equity:
Authorized 5,000,000 shares; issued and outstanding - none	0	0
Authorized 500,000,000 shares, issued and outstanding, net of treasury shares, 121,218,479 and 121,193,599 shares, respectively	47,024	47,024
Additional paid-in capital	1,047,589	1,037,446
Retained earnings	6,703,675	6,595,987
Accumulated other comprehensive income	69,491	55,568
Treasury stock, at cost, 113,899,439 and 113,924,319 shares, respectively	2,688,173	2,688,817
Total stockholders’ equity	5,179,606	5,047,208
Noncontrolling interests	38,935	33,926
Total equity	5,218,541	5,081,134
Total liabilities and equity	$ 23,547,414	$ 23,350,076