Other Income And Other Expense (Details) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
All other income and commissions:
Mortgage banking		$ 5,524,000	$ 761,000	$ 7,395,000	$ 2,721,000
ATM interchange fees		3,081,000	2,998,000	8,918,000	8,784,000
Electronic banking fees		1,398,000	1,479,000	4,176,000	4,366,000
Deferred compensation	[1]	1,038,000	(2,309,000)	2,162,000	(1,311,000)
Letter of credit fees		981,000	978,000	3,157,000	3,633,000
Gain on extinguishment of debt		0	5,794,000	0	5,794,000
Other		5,518,000	3,550,000	10,594,000	13,096,000
Total		17,540,000	13,251,000	36,402,000	37,083,000
All other expense:
Travel and entertainment		2,478,000	2,451,000	7,035,000	6,697,000
Customer relations		1,442,000	1,477,000	4,804,000	4,296,000
Employee training and dues		1,360,000	1,272,000	4,088,000	3,853,000
Supplies		1,158,000	974,000	3,114,000	2,781,000
Tax credit investments		788,000	439,000	2,325,000	1,383,000
Miscellaneous loan costs		676,000	726,000	1,958,000	1,821,000
Litigation and regulatory matters		260,000	10,922,000	25,785,000	173,422,000
Other		8,326,000	8,835,000	30,669,000	26,565,000
Total		$ 16,488,000	$ 27,096,000	$ 79,778,000	$ 220,818,000

[1] (a) Deferred compensation market value adjustments are mirrored by adjustments to employee compensation, incentives, and benefits expense.