Fair Value (Details - Hierarchy table) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	$ 13,020,014	$ 13,448,262
Short-term investments	33,555	46,688
Equities	324,427	443,861
Other invested assets	254,924	190,899
Funds held - directly managed	426,537	399,899
Total	14,059,457	14,529,609
Derivative assets [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	15,119	15,311
Derivative assets [Member] | Foreign currency option contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	1,977
Derivative assets [Member] | Futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	5,588	5,675
Derivative assets [Member] | Insurance-linked securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	9,491	9,428
Derivative assets [Member] | Total return swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	2,953	2,745
Derivative assets [Member] | TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	1,619
Derivative liabilities [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(4,258)	(15,109)
Derivative liabilities [Member] | Futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(1,441)	(140)
Derivative liabilities [Member] | Insurance-linked securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(5,830)	(3,944)
Derivative liabilities [Member] | Total return swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(2,999)	(2,878)
Derivative liabilities [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(25,280)	(24,383)
Derivative liabilities [Member] | TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		(1,462)
Notes And Loan Receivables And Notes Securitization [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	176,970	125,922
Annuities and residuals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	9,116	8,436
Private equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	71,899	71,298
Other invested assets funds held directly managed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	10,292	10,146
Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed		966
Finance [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	44,201	57,679
Consumer noncyclical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	41,544	43,375
Insurance [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	30,033	80,025
Technology [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	28,350	29,384
Industrials [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	25,390	34,264
Consumer cyclical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	25,191	25,871
Communications [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	23,146	22,924
Real estate investment trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities		46,379
Other equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	34,094	28,197
Mutual funds and exchange traded funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	72,478	75,763
US Government and government sponsored enterpises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	2,794,761	2,872,845
Funds held - directly managed	199,258	169,951
US states, territories and municipalities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	780,372	778,326
Non US sovereign government supranational and government related [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	1,197,012	1,332,925
Funds held - directly managed	126,363	119,487
Corporate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	4,977,795	5,086,199
Funds held - directly managed	90,624	99,349
Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	1,032,316	1,037,816
Residential mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	2,189,843	2,290,640
Other mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	47,915	49,511
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Short-term investments	0	0
Equities	284,544	385,608
Other invested assets	4,147	5,535
Funds held - directly managed	0	0
Total	288,691	391,143
Quoted prices in active markets for identical assets (Level 1) | Derivative assets [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Derivative assets [Member] | Foreign currency option contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0
Quoted prices in active markets for identical assets (Level 1) | Derivative assets [Member] | Futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	5,588	5,675
Quoted prices in active markets for identical assets (Level 1) | Derivative assets [Member] | Insurance-linked securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Derivative assets [Member] | Total return swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Derivative assets [Member] | TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0
Quoted prices in active markets for identical assets (Level 1) | Derivative liabilities [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Derivative liabilities [Member] | Futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(1,441)	(140)
Quoted prices in active markets for identical assets (Level 1) | Derivative liabilities [Member] | Insurance-linked securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Derivative liabilities [Member] | Total return swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Derivative liabilities [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Derivative liabilities [Member] | TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
Quoted prices in active markets for identical assets (Level 1) | Notes And Loan Receivables And Notes Securitization [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Annuities and residuals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Private equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Quoted prices in active markets for identical assets (Level 1) | Other invested assets funds held directly managed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	0	0
Quoted prices in active markets for identical assets (Level 1) | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed		0
Quoted prices in active markets for identical assets (Level 1) | Finance [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	18,326	29,422
Quoted prices in active markets for identical assets (Level 1) | Consumer noncyclical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	41,544	43,375
Quoted prices in active markets for identical assets (Level 1) | Insurance [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	27,382	72,226
Quoted prices in active markets for identical assets (Level 1) | Technology [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	21,366	21,177
Quoted prices in active markets for identical assets (Level 1) | Industrials [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	25,390	26,863
Quoted prices in active markets for identical assets (Level 1) | Consumer cyclical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	25,191	25,871
Quoted prices in active markets for identical assets (Level 1) | Communications [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	21,109	20,939
Quoted prices in active markets for identical assets (Level 1) | Real estate investment trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities		46,379
Quoted prices in active markets for identical assets (Level 1) | Other equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	34,094	28,197
Quoted prices in active markets for identical assets (Level 1) | Mutual funds and exchange traded funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	70,142	71,159
Quoted prices in active markets for identical assets (Level 1) | US Government and government sponsored enterpises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Funds held - directly managed	0	0
Quoted prices in active markets for identical assets (Level 1) | US states, territories and municipalities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Quoted prices in active markets for identical assets (Level 1) | Non US sovereign government supranational and government related [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Funds held - directly managed	0	0
Quoted prices in active markets for identical assets (Level 1) | Corporate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Funds held - directly managed	0	0
Quoted prices in active markets for identical assets (Level 1) | Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Quoted prices in active markets for identical assets (Level 1) | Residential mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Quoted prices in active markets for identical assets (Level 1) | Other mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	12,504,952	12,939,716
Short-term investments	33,555	46,688
Equities	7,117	20,697
Other invested assets	(9,823)	(25,643)
Funds held - directly managed	416,245	389,753
Total	12,952,046	13,371,211
Significant other observable inputs (Level 2) | Derivative assets [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	15,119	15,311
Significant other observable inputs (Level 2) | Derivative assets [Member] | Foreign currency option contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	1,977
Significant other observable inputs (Level 2) | Derivative assets [Member] | Futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant other observable inputs (Level 2) | Derivative assets [Member] | Insurance-linked securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant other observable inputs (Level 2) | Derivative assets [Member] | Total return swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant other observable inputs (Level 2) | Derivative assets [Member] | TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	1,619
Significant other observable inputs (Level 2) | Derivative liabilities [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(4,258)	(15,109)
Significant other observable inputs (Level 2) | Derivative liabilities [Member] | Futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant other observable inputs (Level 2) | Derivative liabilities [Member] | Insurance-linked securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant other observable inputs (Level 2) | Derivative liabilities [Member] | Total return swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant other observable inputs (Level 2) | Derivative liabilities [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(25,280)	(24,383)
Significant other observable inputs (Level 2) | Derivative liabilities [Member] | TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		(1,462)
Significant other observable inputs (Level 2) | Notes And Loan Receivables And Notes Securitization [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	1,000	0
Significant other observable inputs (Level 2) | Annuities and residuals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant other observable inputs (Level 2) | Private equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant other observable inputs (Level 2) | Other invested assets funds held directly managed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	0	0
Significant other observable inputs (Level 2) | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed		966
Significant other observable inputs (Level 2) | Finance [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	4,466	5,497
Significant other observable inputs (Level 2) | Consumer noncyclical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant other observable inputs (Level 2) | Insurance [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	2,651	7,799
Significant other observable inputs (Level 2) | Technology [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant other observable inputs (Level 2) | Industrials [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	7,401
Significant other observable inputs (Level 2) | Consumer cyclical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant other observable inputs (Level 2) | Communications [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant other observable inputs (Level 2) | Real estate investment trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities		0
Significant other observable inputs (Level 2) | Other equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant other observable inputs (Level 2) | Mutual funds and exchange traded funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant other observable inputs (Level 2) | US Government and government sponsored enterpises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	2,794,761	2,872,845
Funds held - directly managed	199,258	169,951
Significant other observable inputs (Level 2) | US states, territories and municipalities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	639,799	639,479
Significant other observable inputs (Level 2) | Non US sovereign government supranational and government related [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	1,197,012	1,332,925
Funds held - directly managed	126,363	119,487
Significant other observable inputs (Level 2) | Corporate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	4,977,795	5,086,199
Funds held - directly managed	90,624	99,349
Significant other observable inputs (Level 2) | Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	657,827	668,117
Significant other observable inputs (Level 2) | Residential mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	2,189,843	2,290,640
Significant other observable inputs (Level 2) | Other mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	47,915	49,511
Significant unobservable inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	515,062	508,546
Short-term investments	0	0
Equities	32,766	37,556
Other invested assets	260,600	211,007
Funds held - directly managed	10,292	10,146
Total	818,720	767,255
Significant unobservable inputs (Level 3) [Member] | Derivative assets [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant unobservable inputs (Level 3) [Member] | Derivative assets [Member] | Foreign currency option contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0
Significant unobservable inputs (Level 3) [Member] | Derivative assets [Member] | Futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant unobservable inputs (Level 3) [Member] | Derivative assets [Member] | Insurance-linked securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	9,491	9,428
Significant unobservable inputs (Level 3) [Member] | Derivative assets [Member] | Total return swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	2,953	2,745
Significant unobservable inputs (Level 3) [Member] | Derivative assets [Member] | TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0
Significant unobservable inputs (Level 3) [Member] | Derivative liabilities [Member] | Foreign exchange forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant unobservable inputs (Level 3) [Member] | Derivative liabilities [Member] | Futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant unobservable inputs (Level 3) [Member] | Derivative liabilities [Member] | Insurance-linked securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(5,830)	(3,944)
Significant unobservable inputs (Level 3) [Member] | Derivative liabilities [Member] | Total return swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	(2,999)	(2,878)
Significant unobservable inputs (Level 3) [Member] | Derivative liabilities [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	0	0
Significant unobservable inputs (Level 3) [Member] | Derivative liabilities [Member] | TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets		0
Significant unobservable inputs (Level 3) [Member] | Notes And Loan Receivables And Notes Securitization [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	175,970	125,922
Significant unobservable inputs (Level 3) [Member] | Annuities and residuals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	9,116	8,436
Significant unobservable inputs (Level 3) [Member] | Private equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets	71,899	71,298
Significant unobservable inputs (Level 3) [Member] | Other invested assets funds held directly managed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed	10,292	10,146
Significant unobservable inputs (Level 3) [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Funds held - directly managed		0
Significant unobservable inputs (Level 3) [Member] | Finance [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	21,409	22,760
Significant unobservable inputs (Level 3) [Member] | Consumer noncyclical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant unobservable inputs (Level 3) [Member] | Insurance [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant unobservable inputs (Level 3) [Member] | Technology [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	6,984	8,207
Significant unobservable inputs (Level 3) [Member] | Industrials [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant unobservable inputs (Level 3) [Member] | Consumer cyclical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant unobservable inputs (Level 3) [Member] | Communications [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	2,037	1,985
Significant unobservable inputs (Level 3) [Member] | Real estate investment trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities		0
Significant unobservable inputs (Level 3) [Member] | Other equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	0	0
Significant unobservable inputs (Level 3) [Member] | Mutual funds and exchange traded funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equities	2,336	4,604
Significant unobservable inputs (Level 3) [Member] | US Government and government sponsored enterpises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Funds held - directly managed	0	0
Significant unobservable inputs (Level 3) [Member] | US states, territories and municipalities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	140,573	138,847
Significant unobservable inputs (Level 3) [Member] | Non US sovereign government supranational and government related [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Funds held - directly managed	0	0
Significant unobservable inputs (Level 3) [Member] | Corporate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Funds held - directly managed	0	0
Significant unobservable inputs (Level 3) [Member] | Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	374,489	369,699
Significant unobservable inputs (Level 3) [Member] | Residential mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Significant unobservable inputs (Level 3) [Member] | Other mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	$ 0	$ 0