Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
ASSETS:
Fixed maturities - available for sale, at market value (amortized cost: 2012, $5,289,619; 2011, $4,880,654)	$ 5,531,410	$ 5,107,028
Fixed maturities - available for sale, at fair value	41,470	113,606
Equity securities - available for sale, at market value (cost: 2012, $15; 2011, $15)	13	10
Equity securities - available for sale, at fair value	1,199,848	1,207,053
Short-term investments	465,550	423,663
Other invested assets (cost: 2012, $420,744; 2011, $379,342)	420,744	379,342
Other invested assets, at fair value	1,068,711	817,352
Cash	347,720	348,267
Total investments and cash	9,075,466	8,396,321
Accrued investment income	54,914	55,849
Premiums receivable	1,001,267	856,375
Reinsurance receivables - unaffiliated	650,261	570,128
Reinsurance receivables - affiliated	2,976,992	2,901,174
Funds held by reinsureds	161,694	176,156
Deferred acquisition costs	97,522	166,806
Prepaid reinsurance premiums	557,460	625,391
Deferred tax asset	214,175	366,490
Income taxes recoverable	61,244	39,014
Other assets	236,955	195,476
TOTAL ASSETS	15,087,950	14,349,180
LIABILITIES:
Reserve for losses and loss adjustment expenses	8,143,055	8,290,619
Unearned premium reserve	1,093,822	1,239,705
Funds held under reinsurance treaties	90,079	123,479
Losses in the course of payment	179,774	11,002
Commission reserves	39,324	40,353
Other net payable to reinsurers	900,794	629,871
5.4% Senior notes due 10/15/2014	249,907	249,858
6.6% Long term notes due 5/1/2067	238,357	238,354
Junior subordinated debt securities payable	329,897	329,897
Accrued interest on debt and borrowings	4,781	4,781
Unsettled securities payable	48,830	8,793
Other liabilities	290,724	241,075
Total liabilities	11,609,344	11,407,787
Commitments and Contingencies (Note 16)
STOCKHOLDER'S EQUITY:
Common stock, par value: $0.01; 3,000 shares authorized; 1,000 shares issued and outstanding (2012 and 2011)
Additional paid-in capital	340,223	333,416
Accumulated other comprehensive income (loss), net of deferred income tax expense (benefit) of $99,544 at 2012 and $94,118 at 2011	184,867	174,790
Retained earnings	2,953,516	2,433,187
Total stockholder's equity	3,478,606	2,941,393
TOTAL LIABILITIES AND STOCKHOLDER'S EQUITY	$ 15,087,950	$ 14,349,180