Investments (Details 1) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	$ 393,677	$ 1,913,235
Less than 12 months, Unrealized losses	(6,459)	(85,659)
12 months or more, Fair value	913,740	171,280
12 months or more, Unrealized losses	(25,453)	(19,562)
Total, Fair value	1,307,417	2,084,515
Total, Unrealized losses	(31,912)	(105,221)
US Government and Government Agency Securities [Member]
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	5,838	23,717
Less than 12 months, Unrealized losses	(6)	(495)
12 months or more, Fair value	11,410	0
12 months or more, Unrealized losses	(200)	0
Total, Fair value	17,248	23,717
Total, Unrealized losses	(206)	(495)
Fixed Maturity Securities of States, Municipalities and Political Subdivisions Securities [Member]
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	6,015	136,160
Less than 12 months, Unrealized losses	(34)	(5,277)
12 months or more, Fair value	38,173	8,997
12 months or more, Unrealized losses	(875)	(702)
Total, Fair value	44,188	145,157
Total, Unrealized losses	(909)	(5,979)
Special Purpose Revenue Bonds Of States Municipalities And Political Subdivisions [Member]
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	51,330	684,560
Less than 12 months, Unrealized losses	(200)	(35,832)
12 months or more, Fair value	327,557	83,228
12 months or more, Unrealized losses	(7,382)	(10,926)
Total, Fair value	378,887	767,788
Total, Unrealized losses	(7,582)	(46,758)
Corporate Securities [Member]
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	73,935	277,853
Less than 12 months, Unrealized losses	(366)	(8,202)
12 months or more, Fair value	105,399	35,437
12 months or more, Unrealized losses	(3,762)	(2,807)
Total, Fair value	179,334	313,290
Total, Unrealized losses	(4,128)	(11,009)
Residential Mortgage Backed Securities [Member]
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	58,198	306,874
Less than 12 months, Unrealized losses	(272)	(15,861)
12 months or more, Fair value	259,170	31,687
12 months or more, Unrealized losses	(8,591)	(4,075)
Total, Fair value	317,368	338,561
Total, Unrealized losses	(8,863)	(19,936)
Commercial Mortgage Backed Securities [Member]
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	0	203,347
Less than 12 months, Unrealized losses	0	(12,611)
12 months or more, Fair value	150,806	4,915
12 months or more, Unrealized losses	(3,899)	(725)
Total, Fair value	150,806	208,262
Total, Unrealized losses	(3,899)	(13,336)
Asset-backed Securities [Member]
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	115,769	126,922
Less than 12 months, Unrealized losses	(927)	(1,587)
12 months or more, Fair value	7,080	0
12 months or more, Unrealized losses	(165)	0
Total, Fair value	122,849	126,922
Total, Unrealized losses	(1,092)	(1,587)
Foreign Government Securities [Member]
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	19,363	78,182
Less than 12 months, Unrealized losses	(55)	(357)
12 months or more, Fair value	7,193	0
12 months or more, Unrealized losses	(48)	0
Total, Fair value	26,556	78,182
Total, Unrealized losses	(103)	(357)
Equity Securities [Member]
Gross unrealized losses and fair value of all available for sale securities that were in a continuous loss position
Less than 12 months, Fair value	63,229	75,620
Less than 12 months, Unrealized losses	(4,599)	(5,437)
12 months or more, Fair value	6,952	7,016
12 months or more, Unrealized losses	(531)	(327)
Total, Fair value	70,181	82,636
Total, Unrealized losses	$ (5,130)	$ (5,764)