Investments - Schedule of Unrealized Loss on Investments (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Vaule	$ 5,332	$ 207,361
Less than 12 months, Unrealized Losses	14	8,678
12 months or more, Fair Value	178,543	28,605
12 months or more, Unrealized Losses	5,055	2,655
Total, Fair Value	183,875	235,966
Total, Unrealized Losses	5,069	11,333
Obligations of U.S. government sponsored enterprises
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Vaule	0	30,221
Less than 12 months, Unrealized Losses	0	388
12 months or more, Fair Value	24,870	0
12 months or more, Unrealized Losses	124	0
Total, Fair Value	24,870	30,221
Total, Unrealized Losses	124	388
Obligations of the state and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Vaule	1,180	17,141
Less than 12 months, Unrealized Losses	3	952
12 months or more, Fair Value	17,047	7,168
12 months or more, Unrealized Losses	839	809
Total, Fair Value	18,227	24,309
Total, Unrealized Losses	842	1,761
Residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Vaule	4,152	159,999
Less than 12 months, Unrealized Losses	11	7,338
12 months or more, Fair Value	136,626	21,437
12 months or more, Unrealized Losses	4,092	1,846
Total, Fair Value	140,778	181,436
Total, Unrealized Losses	$ 4,103	$ 9,184