Fair Value of Assets and Liabilities (Summary of Changes in Level Three Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Loans Held For Investment
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 0	$ 0
Total net gains (losses) included in Net income	437
Total net gains (losses) included in Other comprehensive income	0	0
Issuances	0
Sales	0
Net transfers into (out of) Level 3	21,700
Ending Balance	22,137	0
Mortgage Servicing Rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	9,092	8,435
Total net gains (losses) included in Net income	10,011	657
Issuances	0
Sales	0
Ending Balance	19,103	9,092
Derivative Financial Instruments, Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	7,021	9,153
Total net gains (losses) included in Net income	(4,730)	(2,132)
Total net gains (losses) included in Other comprehensive income	0
Issuances	0
Sales	0
Ending Balance	2,291	7,021
Municipal
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	68,613	58,953
Total net gains (losses) included in Other comprehensive income	(949)	(1,198)
Purchases	31,031	33,998
Issuances	0
Sales	0
Settlements	(19,069)	(23,140)
Ending Balance	79,626	68,613
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	25,199	23,711
Total net gains (losses) included in Other comprehensive income	(12)	1,488
Issuances	0
Sales	(25,187)
Ending Balance	$ 0	$ 25,199