Basis of Presentation (Narrative) (Details) - USD ($) $ in Thousands	Aug. 23, 2007	Jun. 21, 2005	Sep. 30, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Senior unsecured notes due 2029			$ 49,132	$ 49,058
Right of use asset			14,467	16,044
Operating lease liabilities			16,348	$ 17,347
Hallmark Statutory Trust I [Member]
Variable Interest Entity [Line Items]
Proceeds from issuance of trust preferred securities	$ 25,000	$ 30,000
Senior unsecured notes due 2029 [Member]
Variable Interest Entity [Line Items]
Senior unsecured notes due 2029			49,100
Notes Payable, Fair Value Disclosure			52,600
Subordinated Debt [Member]
Variable Interest Entity [Line Items]
Trust preferred securities, carrying value			55,900
Trust preferred securities, fair value			$ 30,300
Subordinated Debt [Member] | Hallmark Statutory Trust I [Member]
Variable Interest Entity [Line Items]
Payments to acquire trust preferred investments	$ 25,800	$ 30,900