Fair Value Measurements - Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Debt Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 1,228	$ 1,846
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as losses incurred, net	0	0
Purchases	0	7
Sales	(36)	(62)
Balance at end of period	1,228	1,846	$ 1,192	$ 1,791
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	2,855	321
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as losses incurred, net	0	0
Purchases	3,091	0
Sales	(2,525)	0
Balance at end of period	2,855	321	3,421	321
Total Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	4,083	2,167
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as losses incurred, net	0	0
Purchases	3,091	7
Sales	(2,561)	(62)
Balance at end of period	4,083	2,167	4,613	2,112
Real Estate Acquired
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	12,149	12,658
Total realized/unrealized gains (losses) [Abstract]
Included in earnings and reported as losses incurred, net	(293)	(503)
Purchases	12,267	10,797
Sales	(11,274)	(12,055)
Balance at end of period	$ 12,149	$ 12,658	$ 12,849	$ 10,897