Basis of Presentation (Narrative) (Details) - USD ($) $ in Millions			6 Months Ended
	Aug. 23, 2007	Jun. 21, 2005	Jun. 30, 2015
Hallmark Statutory Trust I [Member]
Variable Interest Entity [Line Items]
Proceeds from issuance of trust preferred securities		$ 30.0
Hallmark Statutory Trust II [Member]
Variable Interest Entity [Line Items]
Proceeds from issuance of trust preferred securities	$ 25.0
Subordinated Debt [Member]
Variable Interest Entity [Line Items]
Trust preferred securities, carrying value			$ 56.7
Trust preferred securities, fair value			$ 48.3
Current yield to maturity percentage			8.00%
Subordinated Debt [Member] | Hallmark Statutory Trust I [Member]
Variable Interest Entity [Line Items]
Payments to acquire trust preferred investments		$ 30.9
Subordinated Debt [Member] | Hallmark Statutory Trust II [Member]
Variable Interest Entity [Line Items]
Payments to acquire trust preferred investments	$ 25.8