Accounting Policies (Narrative) (Details) $ in Thousands				12 Months Ended
	Jan. 01, 2018 USD ($)	Aug. 23, 2007 USD ($)	Jun. 21, 2005 USD ($)	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Number of Reportable Segments | segment				3
Amortized				$ 141,000	$ 120,300
Deferred Policy Ceded Commission, Acquisition Cost				160,800	88,800
Amortized, Ceded				(153,700)	(82,900)
Net				(8,700)	1,700
Deferred policy acquisition costs, disposition				(156,800)	(124,500)
Property and equipment, gross				$ 34,600	27,000
Property and equipment, depreciation method				straight-line method
Depreciation				$ 3,000	2,700
Property and equipment, accumulated depreciation				23,800	20,800
Policy fees				8,700	$ 6,500
Operating lease right-of-use assets				$ 16,044
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]				Other Assets
Lease liabilities				$ 17,347
Operating Lease, Liability, Statement of Financial Position [Extensible List]				Accounts Payable and Accrued Liabilities
Accumulated Other Comprehensive Income (Loss) [Member]
Reclassification out of AOCI as a result of Tax Act						$ 2,619
Hallmark Statutory Trust I [Member]
Proceeds from issuance of trust preferred securities			$ 30,000
Hallmark Statutory Trust II [Member]
Proceeds from issuance of trust preferred securities		$ 25,000
Minimum [Member]
Property and equipment, estimated useful lives				3 years	3 years
Maximum [Member]
Property and equipment, estimated useful lives				10 years	10 years
Accounting Standards Update 2016-01 [Member]
Net after-tax unrealized gains on equity investments	$ 17,000
Accounting Standards Update 2016-02 [Member] | Leaseholds and Leasehold Improvements [Member]
Property and equipment, gross				$ 3,400
Senior unsecured notes due 2029 [Member]
Long-term debt, gross				49,100
Notes Payable, Fair Value Disclosure				49,800
Subordinated Debt [Member]
Trust preferred securities, fair value				41,700	$ 45,600
Trust preferred securities, carrying value				$ 55,900	$ 55,800
Subordinated Debt [Member] | Hallmark Statutory Trust I [Member]
Payments to acquire trust preferred investments			$ 30,900
Subordinated Debt [Member] | Hallmark Statutory Trust II [Member]
Payments to acquire trust preferred investments		$ 25,800