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 - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Pooled trust preferred securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 706	$ 4,088
Unrealized adjustment to fair value	(286)	366
Sales		(3,633)
Discount accretion	2	2
Balance, end of period	422	706
Pooled trust preferred securities | Call Option [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Settlements - calls		(117)
Single-issuer trust preferred securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	2,630	3,820
Unrealized adjustment to fair value	(190)	(230)
Sales		0
Discount accretion	10	10
Balance, end of period	2,450	2,630
Single-issuer trust preferred securities | Call Option [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Settlements - calls		(970)
Auction rate securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	98,059	100,941
Unrealized adjustment to fair value	(1,246)	(903)
Sales		0
Discount accretion	443	467
Balance, end of period	$ 97,256	98,059
Auction rate securities | Call Option [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Settlements - calls		$ (2,446)