Fair Value Measurements (Summarize Changes in Level 3 Assets) (Details) (Level 3, USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	$ 62,022	$ 82,541
Assets, earnings	(1,153)	(3,905)
Assets, other comprehensive income	(867)	11,455
Assets, purchases	4,338	283
Assets, (sales)	(3,601)	(11,274)
Assets, maturities	(4,720)	(17,171)
Assets, transfer out	0	93
Assets, ending balance	56,019	62,022
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Liabilities, beginning balance	20	21
Liabilities, earnings	(4)	(1)
Liabilities, Other Comprehensive Income	0	0
Liabilities, purchases	4	0
Liabilities, (sales)	20	0
Liabilities, maturities	0	0
Liabilities, transfer out	0	0
Liabilities, ending balance	0	20
Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	59,065	67,828
Assets, earnings	(64)	(1,497)
Assets, other comprehensive income	(867)	9,622
Assets, purchases	84	283
Assets, (sales)	(2,577)	0
Assets, maturities	(4,720)	(17,171)
Assets, transfer out	0	0
Assets, ending balance	50,921	59,065
Corporate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	59,065	67,828
Assets, earnings	(64)	(1,497)
Assets, other comprehensive income	(867)	9,622
Assets, purchases	84	283
Assets, (sales)	(2,577)	0
Assets, maturities	(4,720)	(17,171)
Assets, transfer out	0	0
Assets, ending balance	50,921	59,065
Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	2,029	13,862
Assets, earnings	(274)	1,126
Assets, other comprehensive income	0	(1,737)
Assets, purchases	3,430	0
Assets, (sales)	(170)	(11,222)
Assets, maturities	0	0
Assets, transfer out	0	0
Assets, ending balance	5,015	2,029
Preferred stocks
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	621	12,303
Assets, earnings	(274)	1,126
Assets, other comprehensive income	0	(1,737)
Assets, purchases	3,430	0
Assets, (sales)	0	(11,071)
Assets, maturities	0	0
Assets, transfer out	0	0
Assets, ending balance	3,777	621
Common stocks
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	1,408	1,559
Assets, earnings	0	0
Assets, other comprehensive income	0	0
Assets, purchases	0	0
Assets, (sales)	(170)	(151)
Assets, maturities	0	0
Assets, transfer out	0	0
Assets, ending balance	1,238	1,408
Trading Assets, Excluding Debt and Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	928	851
Assets, earnings	(815)	(3,534)
Assets, other comprehensive income	0	3,570
Assets, purchases	824	0
Assets, (sales)	(854)	(52)
Assets, maturities	0	0
Assets, transfer out	0	93
Assets, ending balance	$ 83	$ 928