Basis of Presentation (Narrative) (Details) - USD ($) $ in Thousands	Aug. 23, 2007	Jun. 21, 2005	Mar. 31, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Senior unsecured notes due 2029, carrying value			$ 49,180	$ 49,156
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, carrying value			49,200
Senior unsecured notes due 2029, fair value			52,200
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