Fair Value of Financial Instruments (Level 3 Securities) (Details) (Recurring [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 23,540
Unrealized gains	2,483	[1]
Disposals	(365)
Ending Balance	25,658
States, Municipalities and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	750
Unrealized gains	125	[1]
Disposals	0
Ending Balance	875
Foreign Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	558
Unrealized gains	63	[1]
Disposals	0
Ending Balance	621
Corporate Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	16,108
Unrealized gains	2,249	[1]
Disposals	(272)
Ending Balance	18,085
Asset-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	2,488
Unrealized gains	46	[1]
Disposals	(93)
Ending Balance	2,441
Equities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	3,636
Unrealized gains	0	[1]
Disposals	0
Ending Balance	$ 3,636

[1] Realized gains are recorded as a component of earnings whereas unrealized gains are recorded as a component of comprehensive income.