Fair Value (Details 3) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair value by pricing source
Available-for-sale securities	$ 704,375	$ 599,941
Fair value measurements on a recurring basis
Fair value by pricing source
Available-for-sale securities	704,375	599,941
Total	708,339	604,467
Fair value measurements on a recurring basis | Fixed maturities
Fair value by pricing source
Available-for-sale securities	695,355	587,209
Fair value measurements on a recurring basis | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	689,205
Fair value measurements on a recurring basis | Fixed maturities | Priced via market comparables/broker quotes
Fair value by pricing source
Available-for-sale securities	6,150
Fair value measurements on a recurring basis | Common stock
Fair value by pricing source
Available-for-sale securities	9,020	12,732
Fair value measurements on a recurring basis | Common stock | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	9,020
Fair value measurements on a recurring basis | Real estate
Fair value by pricing source
Other investments	3,964	4,526
Fair value measurements on a recurring basis | Real estate | Priced via unobservable inputs
Fair value by pricing source
Other investments	3,964
Fair value measurements on a recurring basis | Level 1
Fair value by pricing source
Available-for-sale securities	9,020	12,732
Total	9,020	12,732
Fair value measurements on a recurring basis | Level 1 | Fixed maturities
Fair value by pricing source
Available-for-sale securities	0	0
Fair value measurements on a recurring basis | Level 1 | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	0
Fair value measurements on a recurring basis | Level 1 | Fixed maturities | Priced via market comparables/broker quotes
Fair value by pricing source
Available-for-sale securities	0
Fair value measurements on a recurring basis | Level 1 | Common stock
Fair value by pricing source
Available-for-sale securities	9,020	12,732
Fair value measurements on a recurring basis | Level 1 | Common stock | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	9,020
Fair value measurements on a recurring basis | Level 2
Fair value by pricing source
Available-for-sale securities	680,045	578,563
Total	680,045	578,563
Fair value measurements on a recurring basis | Level 2 | Fixed maturities
Fair value by pricing source
Available-for-sale securities	680,045	578,563
Fair value measurements on a recurring basis | Level 2 | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	679,955
Fair value measurements on a recurring basis | Level 2 | Fixed maturities | Priced via market comparables/broker quotes
Fair value by pricing source
Available-for-sale securities	90
Fair value measurements on a recurring basis | Level 2 | Common stock
Fair value by pricing source
Available-for-sale securities	0	0
Fair value measurements on a recurring basis | Level 2 | Common stock | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	0
Fair value measurements on a recurring basis | Level 3
Fair value by pricing source
Available-for-sale securities	15,310	8,646
Total	15,310	8,646
Fair value measurements on a recurring basis | Level 3 | Non-binding broker quotes classified within Level 3
Fair value by pricing source
Available-for-sale securities	15,300
Fair value measurements on a recurring basis | Level 3 | Fixed maturities
Fair value by pricing source
Available-for-sale securities	15,310	8,646
Fair value measurements on a recurring basis | Level 3 | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	9,250
Fair value measurements on a recurring basis | Level 3 | Fixed maturities | Priced via market comparables/broker quotes
Fair value by pricing source
Available-for-sale securities	6,060
Fair value measurements on a recurring basis | Level 3 | Common stock
Fair value by pricing source
Available-for-sale securities	0	$ 0
Fair value measurements on a recurring basis | Level 3 | Common stock | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	0
Fair value measurements on a nonrecurring basis
Fair value by pricing source
Total	$ 0