Past Due Loans, Allowance For Credit Losses, Impaired Loans and TDRS (Details) - Allowance for Credit Losses - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	$ 73,279	$ 79,942	$ 74,510	$ 87,121
Charge-offs	(4,357)	(17,106)	(22,516)	(35,444)
Recoveries	1,294	1,159	5,670	5,536
Net charge-offs	(3,063)	(15,947)	(16,846)	(29,908)
Provision for loan and covered loan losses and other	3,509	10,727	16,061	17,509
Ending balance	73,725	74,722	73,725	74,722
Commercial, Industrial, and Agricultural
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	33,729	29,194	29,458	30,381
Charge-offs	(1,948)	(9,763)	(13,524)	(15,542)
Recoveries	347	716	1,993	3,135
Net charge-offs	(1,601)	(9,047)	(11,531)	(12,407)
Provision for loan and covered loan losses and other	3,247	10,458	17,448	12,631
Ending balance	35,375	30,605	35,375	30,605
Office Retail and Industrial
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	11,345	11,831	10,992	10,405
Charge-offs	(563)	(2,514)	(2,613)	(7,108)
Recoveries	106	55	460	403
Net charge-offs	(457)	(2,459)	(2,153)	(6,705)
Provision for loan and covered loan losses and other	967	265	3,016	5,937
Ending balance	11,855	9,637	11,855	9,637
Multi-Family
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	2,451	2,048	2,249	2,017
Charge-offs	(68)	(26)	(565)	(383)
Recoveries	1	0	8	3
Net charge-offs	(67)	(26)	(557)	(380)
Provision for loan and covered loan losses and other	226	(65)	918	320
Ending balance	2,610	1,957	2,610	1,957
Construction
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	1,890	4,885	2,297	6,316
Charge-offs	0	(157)	(15)	(1,052)
Recoveries	114	0	334	160
Net charge-offs	114	(157)	319	(892)
Provision for loan and covered loan losses and other	(559)	(3,130)	(1,171)	(3,826)
Ending balance	1,445	1,598	1,445	1,598
Other Commercial Real Estate
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	6,367	8,585	8,327	10,817
Charge-offs	(598)	(1,363)	(2,442)	(3,695)
Recoveries	506	108	1,902	341
Net charge-offs	(92)	(1,255)	(540)	(3,354)
Provision for loan and covered loan losses and other	(181)	189	(1,693)	56
Ending balance	6,094	7,519	6,094	7,519
Total Consumer Loans
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	10,820	12,440	12,145	13,010
Charge-offs	(1,172)	(3,148)	(2,723)	(7,005)
Recoveries	213	150	853	502
Net charge-offs	(959)	(2,998)	(1,870)	(6,503)
Provision for loan and covered loan losses and other	1,144	3,699	730	6,634
Ending balance	11,005	13,141	11,005	13,141
Covered Loans
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	4,861	9,343	7,226	12,559
Charge-offs	(8)	(135)	(634)	(659)
Recoveries	7	130	120	992
Net charge-offs	(1)	(5)	(514)	333
Provision for loan and covered loan losses and other	(744)	(689)	(2,596)	(4,243)
Ending balance	4,116	8,649	4,116	8,649
Reserve for Unfunded Commitments
Allowance for Credit Losses by Portfolio Segment [Roll Forward]
Beginning balance	1,816	1,616	1,816	1,616
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net charge-offs	0	0	0	0
Provision for loan and covered loan losses and other	(591)	0	(591)	0
Ending balance	$ 1,225	$ 1,616	$ 1,225	$ 1,616