Fair Value (Details 3) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair value by pricing source
Available-for-sale securities	$ 749,266	$ 713,291
Fair value measurements on a recurring basis
Fair value by pricing source
Available-for-sale securities	749,266	713,291
Total	753,604	717,703
Fair value measurements on a recurring basis | Fixed maturities
Fair value by pricing source
Available-for-sale securities	749,266	707,341
Fair value measurements on a recurring basis | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	749,266
Fair value measurements on a recurring basis | Real estate
Fair value by pricing source
Other investments	4,338	4,412
Fair value measurements on a recurring basis | Real estate | Priced via unobservable inputs
Fair value by pricing source
Other investments	4,338
Fair value measurements on a recurring basis | Level 1
Fair value by pricing source
Available-for-sale securities	0	5,950
Total	0	5,950
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 2
Fair value by pricing source
Available-for-sale securities	741,351	697,989
Total	741,351	697,989
Fair value measurements on a recurring basis | Level 2 | Fixed maturities
Fair value by pricing source
Available-for-sale securities	741,351	697,989
Fair value measurements on a recurring basis | Level 2 | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	741,351
Fair value measurements on a recurring basis | Level 3
Fair value by pricing source
Available-for-sale securities	7,915	9,352
Total	7,915	9,352
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	7,900
Fair value measurements on a recurring basis | Level 3 | Fixed maturities
Fair value by pricing source
Available-for-sale securities	7,915	$ 9,352
Fair value measurements on a recurring basis | Level 3 | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	7,915
Fair value measurements on a nonrecurring basis
Fair value by pricing source
Total	$ 0