Unaudited Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Investments:
Fixed maturities available for sale, at fair value (amortized cost: $9,619,842 and $9,567,290)	$ 9,570,583	$ 9,839,988
Short-term investments available for sale, at fair value (amortized cost: $1,095,497 and $719,848)	1,091,032	722,121
Investment of funds received under securities lending, at fair value (amortized cost: $39,079 and $42,302)	41,062	42,531
Equity securities available for sale, at fair value (cost: $410,219 and $298,414)	438,038	312,749
Other investments available for sale, at fair value (cost: $555,422 and $519,955)	569,407	549,280
Investments accounted for using the fair value option	1,065,684	917,466
Investments accounted for using the equity method	208,796	307,105
Total investments	12,984,602	12,691,240
Cash	375,119	371,041
Accrued investment income	68,413	71,748
Investment in joint venture (cost: $100,000)	108,710	107,284
Fixed maturities and short-term investments pledged under securities lending, at fair value	47,763	50,848
Premiums receivable	876,989	688,873
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses	1,849,891	1,870,037
Contractholder receivables	947,887	865,728
Prepaid reinsurance premiums	330,854	298,484
Deferred acquisition costs, net	313,010	262,822
Receivable for securities sold	447,545	19,248
Other assets	566,900	519,409
Total Assets	18,917,683	17,816,762
Liabilities
Reserve for losses and loss adjustment expenses	8,808,594	8,933,292
Unearned premiums	1,921,849	1,647,978
Reinsurance balances payable	210,113	188,546
Contractholder payables	947,887	865,728
Senior notes	300,000	300,000
Revolving credit agreement borrowings	100,000	100,000
Securities lending payable	49,135	52,356
Payable for securities purchased	853,156	37,788
Other liabilities	492,631	522,196
Total Liabilities	13,683,365	12,647,884
Commitments and Contingencies
Shareholders’ Equity
Non-cumulative preferred shares	325,000	325,000
Common shares ($0.0033 par, shares issued: 169,245,371 and 168,255,572)	564	561
Additional paid-in capital	272,955	227,778
Retained earnings	5,776,808	5,354,361
Accumulated other comprehensive income (loss), net of deferred income tax	(49,322)	287,017
Common shares held in treasury, at cost (shares: 35,828,952 and 34,412,959)	(1,091,687)	(1,025,839)
Total Shareholders' Equity	5,234,318	5,168,878
Total Liabilities and Shareholders' Equity	$ 18,917,683	$ 17,816,762