Schedule III. Supplementary Insurance Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Supplementary Insurance Information, by Segment [Line Items]
Deferred Policy Acquisition Costs	$ 105,300		$ 106,654		$ 87,524
Future Policy Benefits, Losses, Claims and Loss Expenses	2,470,087		2,421,332		1,992,421
Unearned Premiums	311,650		288,991		200,341
Earned Premium Revenue	694,994		586,783		469,473
Investment Income, Net	111,905		109,494		111,685
Benefits, Claims, Losses and Settlement Expenses	502,801		462,956		337,025
Amortization of Deferred Policy Acquisition Costs	141,834	[1]	153,176	[1]	111,045	[1]
Other Underwriting Expense	81,125		58,757		41,631
Interest on Policyholders' Accounts	41,409		42,834		42,988
Premiums Written	655,331	[2]	551,923	[2]	414,908	[2]
Amortization of the value of business acquired asset	1,673		25,763		0
Property and Casualty Insurance [Member]
Supplementary Insurance Information, by Segment [Line Items]
Deferred Policy Acquisition Costs	64,947		60,668		44,681
Future Policy Benefits, Losses, Claims and Loss Expenses	971,911		945,051		603,090
Unearned Premiums	311,561		288,868		200,151
Earned Premium Revenue	629,411		533,771		420,373
Investment Income, Net	41,879		35,513		34,787
Benefits, Claims, Losses and Settlement Expenses	439,137		407,831		289,437
Amortization of Deferred Policy Acquisition Costs	134,444	[1]	143,952	[1]	100,310	[1]
Other Underwriting Expense	63,620		46,404		30,313
Interest on Policyholders' Accounts	0		0		0
Premiums Written	655,331	[2]	551,923	[2]	414,908	[2]
Amortization of the value of business acquired asset	1,673		25,763		0
Life Insurance [Member]
Supplementary Insurance Information, by Segment [Line Items]
Deferred Policy Acquisition Costs	40,353	[3]	45,986	[3]	42,843	[3]
Future Policy Benefits, Losses, Claims and Loss Expenses	1,498,176	[3]	1,476,281	[3]	1,389,331	[3]
Unearned Premiums	89	[3]	123	[3]	190	[3]
Earned Premium Revenue	65,583	[3]	53,012	[3]	49,100	[3]
Investment Income, Net	70,026	[3]	73,981	[3]	76,898	[3]
Benefits, Claims, Losses and Settlement Expenses	63,664	[3]	55,125	[3]	47,588	[3]
Amortization of Deferred Policy Acquisition Costs	7,390	[1],[3]	9,224	[1],[3]	10,735	[1],[3]
Other Underwriting Expense	17,505	[3]	12,353	[3]	11,318	[3]
Interest on Policyholders' Accounts	41,409	[3]	42,834	[3]	42,988	[3]
Premiums Written	0	[2],[3]	0	[2],[3]	0	[2],[3]
Mercer Insurance Group [Member]
Supplementary Insurance Information, by Segment [Line Items]
Amortization of the value of business acquired asset	$ 1,673		$ 25,763

[1] 2012 and 2011 include amortization of the value of business acquired asset that was recorded as a result of our acquisition of Mercer Insurance Group, Inc. totaling $1,673 and $25,763, respectively.

[2] Pursuant to Regulation S-X, premiums written does not apply to life insurance companies. Please refer to the Measurement of Results section of Part II, Item 7, for further explanation of this measure.

[3] Annuity deposits are included in future policy benefits, losses, claims and loss expenses.