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		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 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	$ 530	$ 706	$ 4,088
Sales				(3,633)
Unrealized adjustment to fair value	0	0	0	190
(Premium amortization) discount accretion	0	0	0	2
Settlements - calls		0		(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	2,425	3,820	2,630	3,820
Sales				0
Unrealized adjustment to fair value	7	(203)	(204)	(207)
(Premium amortization) discount accretion	3	3	9	7
Settlements - calls		(970)		(970)
Balance, end of period	2,435	2,650	2,435	2,650
Auction Rate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	97,886	98,606	98,059	100,941
Sales				0
Unrealized adjustment to fair value	(318)	(890)	(668)	(978)
(Premium amortization) discount accretion	158	157	335	356
Settlements - calls		0		(2,446)
Balance, end of period	$ 97,726	$ 97,873	$ 97,726	$ 97,873