Schedule V - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Premiums and fees receivable
Movement in Valuation Allowances and Reserves [Roll Forward]
Opening Balance	$ 26,569	$ 22,524	$ 21,446
Additions - Charged to Expense	20,720	10,006	6,281
Deductions - Amounts Written Off	(7,363)	(5,961)	(5,203)
Ending Balance	39,926	26,569	22,524
Due from reinsurers
Movement in Valuation Allowances and Reserves [Roll Forward]
Opening Balance	1,049	1,020	1,144
Additions - Charged to Expense	(29)	20	(24)
Deductions - Amounts Written Off	(10)	9	(100)
Ending Balance	1,010	1,049	1,020
Deferred federal and foreign income taxes
Movement in Valuation Allowances and Reserves [Roll Forward]
Opening Balance	5,457	4,037	1,335
Additions - Charged to Expense	12,663	1,420	2,702
Deductions - Amounts Written Off	(1,501)	0	0
Ending Balance	16,619	5,457	4,037
Loan loss reserves
Valuation and Qualifying Accounts Disclosure [Line Items]
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Provision for Loan Losses				$ 2,486
Movement in Valuation Allowances and Reserves [Roll Forward]
Opening Balance	3,397	2,094
Additions - Charged to Expense	(14)	1,303	(392)
Deductions - Amounts Written Off	0	0	0
Ending Balance	3,383	3,397	2,094
General Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Opening Balance	36,472	29,675	26,411
Additions - Charged to Expense	33,340	12,749	8,567
Deductions - Amounts Written Off	(8,874)	(5,952)	(5,303)
Ending Balance	$ 60,938	$ 36,472	$ 29,675