Basis of Presentation (Narrative) (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended		3 Months Ended
	Jun. 21, 2005	Aug. 23, 2007	Mar. 31, 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			46.0
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