Past Due Loans, Allowance For Credit Losses, Impaired Loans and TDRS (Details) - Allowance for Credit Losses - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	$ 78,375	$ 72,806	$ 74,855	$ 74,510
Charge-offs	(6,133)	(8,106)	(11,322)	(18,159)
Recoveries	1,003	2,579	2,119	4,376
Net charge-offs	(5,130)	(5,527)	(9,203)	(13,783)
Provision for loan losses and other	8,260	6,000	15,853	12,552
Ending balance	81,505	73,279	81,505	73,279
Commercial, Industrial, and Agricultural
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	37,736	32,096	37,074	29,458
Charge-offs	(2,026)	(4,127)	(3,924)	(11,576)
Recoveries	576	854	1,078	1,646
Net charge-offs	(1,450)	(3,273)	(2,846)	(9,930)
Provision for loan losses and other	3,798	4,906	5,856	14,201
Ending balance	40,084	33,729	40,084	33,729
Office, Retail, and Industrial
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	14,412	10,831	13,116	10,992
Charge-offs	(1,641)	(1,894)	(2,165)	(2,050)
Recoveries	8	32	111	354
Net charge-offs	(1,633)	(1,862)	(2,054)	(1,696)
Provision for loan losses and other	206	2,376	1,923	2,049
Ending balance	12,985	11,345	12,985	11,345
Multi-family
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	2,540	2,355	2,462	2,249
Charge-offs	(84)	(469)	(288)	(497)
Recoveries	1	3	26	7
Net charge-offs	(83)	(466)	(262)	(490)
Provision for loan losses and other	469	562	726	692
Ending balance	2,926	2,451	2,926	2,451
Construction
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	2,433	2,076	1,440	2,297
Charge-offs	(8)	(15)	(134)	(15)
Recoveries	20	203	35	220
Net charge-offs	12	188	(99)	205
Provision for loan losses and other	(206)	(374)	898	(612)
Ending balance	2,239	1,890	2,239	1,890
Other Commercial Real Estate
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	6,567	6,298	6,088	8,327
Charge-offs	(879)	(527)	(2,324)	(1,844)
Recoveries	69	1,130	220	1,396
Net charge-offs	(810)	603	(2,104)	(448)
Provision for loan losses and other	1,717	(534)	3,490	(1,512)
Ending balance	7,474	6,367	7,474	6,367
Consumer
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	11,894	11,655	11,812	12,145
Charge-offs	(1,493)	(751)	(2,485)	(1,551)
Recoveries	329	319	649	640
Net charge-offs	(1,164)	(432)	(1,836)	(911)
Provision for loan losses and other	2,273	(403)	3,027	(414)
Ending balance	13,003	10,820	13,003	10,820
Covered Loans
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	1,568	5,679	1,638	7,226
Charge-offs	(2)	(323)	(2)	(626)
Recoveries	0	38	0	113
Net charge-offs	(2)	(285)	(2)	(513)
Provision for loan losses and other	(172)	(533)	(242)	(1,852)
Ending balance	1,394	4,861	1,394	4,861
Reserve for Unfunded Commitments
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	1,225	1,816	1,225	1,816
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net charge-offs	0	0	0	0
Provision for loan losses and other	175	0	175	0
Ending balance	$ 1,400	$ 1,816	$ 1,400	$ 1,816