Fair Value Measurements Changes in Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Level 3 Inputs (Details) - Fair Value, Measurements, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Pooled Trust Preferred Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 706	$ 1,084	$ 706	$ 4,088
Sales		(554)		(3,633)
Unrealized adjustment to fair value	0	0	0	190
(Premium amortization) discount accretion	0	0	0	2
Settlements - calls				(117)
Balance, end of period	706	530	706	530
Single-issuer Trust Preferred Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	2,400	3,820	2,630	3,820
Sales		0		0
Unrealized adjustment to fair value	22	(2)	(211)	(4)
(Premium amortization) discount accretion	3	2	6	4
Settlements - calls				0
Balance, end of period	2,425	3,820	2,425	3,820
Auction Rate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	97,326	98,932	98,059	100,941
Sales		0		0
Unrealized adjustment to fair value	482	(420)	(350)	(88)
(Premium amortization) discount accretion	78	94	177	199
Settlements - calls				(2,446)
Balance, end of period	$ 97,886	$ 98,606	$ 97,886	$ 98,606