Fair Value Measurements Fair Value Measurements (Summarize Changes in Level 3 Assets) (Details) - Level 3 - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	$ 35,939,000	$ 49,634,000
Assets, earnings	(460,000)	2,304,000
Assets, other comprehensive income	(1,542,000)	(4,622,000)
Assets, purchases	72,640,000	19,953,000
Assets, (sales)	(71,866,000)	(33,698,000)
Assets, maturities	1,673,000	3,429,000
Assets, ending balance	13,905,000	35,939,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	9,064,000
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Liabilities, beginning balance	0	0
Liabilities, earnings	0	(20,000)
Liabilities, other comprehensive income	0	0
Liabilities, purchases	0	31,000
Liabilities, (sales)	0	(11,000)
Liabilities, maturities	0	0
Liabilities, ending balance	0	0
Securities Sold, Not yet Purchased [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Equity securities available for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	14,454,000	4,990,000
Assets, earnings	(38,000)	(17,000)
Assets, other comprehensive income	(1,722,000)	(911,000)
Assets, purchases	0	14,773,000
Assets, (sales)	0	(4,381,000)
Assets, ending balance	12,694,000	14,454,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Preferred stocks
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	3,713,000	3,752,000
Assets, earnings	(38,000)	(17,000)
Assets, other comprehensive income	0	0
Assets, purchases	0	3,430,000
Assets, (sales)	0	(3,452,000)
Assets, ending balance	3,675,000	3,713,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Common stocks
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	10,741,000	1,238,000
Assets, earnings	0	0
Assets, other comprehensive income	(1,722,000)	(911,000)
Assets, purchases	0	11,343,000
Assets, (sales)	0	(929,000)
Assets, ending balance	9,019,000	10,741,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	20,765,000	42,864,000
Assets, earnings	15,000	47,000
Assets, other comprehensive income	180,000	(3,711,000)
Assets, purchases	0	238,000
Assets, (sales)	0	(15,244,000)
Assets, maturities	1,673,000	3,429,000
Assets, ending balance	154,000	20,765,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	(19,133,000)	0
Corporate Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	20,765,000	42,864,000
Assets, earnings	15,000	47,000
Assets, other comprehensive income	180,000	(3,711,000)
Assets, purchases	0	238,000
Assets, (sales)	0	(15,244,000)
Assets, maturities	1,673,000	3,429,000
Assets, ending balance	154,000	20,765,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	(19,133,000)	0
Trading Assets, Excluding Debt and Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Assets, beginning balance	720,000	1,780,000
Assets, earnings	(437,000)	2,274,000
Assets, other comprehensive income	0	0
Assets, purchases	72,640,000	4,942,000
Assets, (sales)	(71,866,000)	(14,073,000)
Assets, ending balance	1,057,000	720,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	9,064,000
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	$ (19,133,000)	$ (3,267,000)