Segment Information (Summary Of Certain Operating Information For Reportable Segments) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total net interest income	$ 135,824	$ 128,270	$ 266,537	$ 254,165
Total net interest income, Change in Contribution	7,554		12,372
Total net interest income, Change in Contribution Percentage	6.00%		5.00%
Total non-interest income	63,995	50,935	121,374	97,958
Total non-interest income, Change in Contribution	13,060		23,416
Total non-interest income, Change in Contribution Percentage	26.00%		24.00%
Total net revenue	199,819	179,205	387,911	352,123
Total net revenue, Change in Contribution	20,614		35,788
Total net revenue, Change in Contribution Percentage	12.00%		10.00%
Total segment profit	34,307	25,595	66,359	48,805
Total segment profit, Change in Contribution	8,712		17,554
Total segment profit, Change in Contribution Percentage	34.00%		36.00%
Total assets	17,613,546	16,576,282	17,613,546	16,576,282	17,519,613
Total segment assets, Change in Contribution	1,037,264
Total segment assets, Change in Contribution Percentage	6.00%
Community Banking [Member]
Segment Reporting Information [Line Items]
Total net interest income	127,515	123,016	250,949	244,150
Total net interest income, Change in Contribution	4,499		6,799
Total net interest income, Change in Contribution Percentage	4.00%		3.00%
Total non-interest income	42,602	37,019	82,484	68,805
Total non-interest income, Change in Contribution	5,583		13,679
Total non-interest income, Change in Contribution Percentage	15.00%		20.00%
Total net revenue	170,117	160,035	333,433	312,955
Total net revenue, Change in Contribution	10,082		20,478
Total net revenue, Change in Contribution Percentage	6.00%		7.00%
Total segment profit	34,227	29,414	67,874	56,389
Total segment profit, Change in Contribution	4,813		11,485
Total segment profit, Change in Contribution Percentage	16.00%		20.00%
Total assets	17,339,140	16,234,511	17,339,140	16,234,511
Total segment assets, Change in Contribution	1,104,629
Total segment assets, Change in Contribution Percentage	7.00%
Specialty Finance [Member]
Segment Reporting Information [Line Items]
Total net interest income	31,460	28,694	62,550	56,280
Total net interest income, Change in Contribution	2,766		6,270
Total net interest income, Change in Contribution Percentage	10.00%		11.00%
Total non-interest income	1,789	1,567	3,482	2,938
Total non-interest income, Change in Contribution	222		544
Total non-interest income, Change in Contribution Percentage	14.00%		19.00%
Total net revenue	33,249	30,261	66,032	59,218
Total net revenue, Change in Contribution	2,988		6,814
Total net revenue, Change in Contribution Percentage	10.00%		12.00%
Total segment profit	13,838	10,969	27,612	23,434
Total segment profit, Change in Contribution	2,869		4,178
Total segment profit, Change in Contribution Percentage	26.00%		18.00%
Total assets	4,163,795	3,711,459	4,163,795	3,711,459
Total segment assets, Change in Contribution	452,336
Total segment assets, Change in Contribution Percentage	12.00%
Wealth Management [Member]
Segment Reporting Information [Line Items]
Total net interest income	2,396	2,692	3,660	4,416
Total net interest income, Change in Contribution	(296)		(756)
Total net interest income, Change in Contribution Percentage	(11.00%)		(17.00%)
Total non-interest income	19,071	15,964	36,927	31,201
Total non-interest income, Change in Contribution	3,107		5,726
Total non-interest income, Change in Contribution Percentage	19.00%		18.00%
Total net revenue	21,467	18,656	40,587	35,617
Total net revenue, Change in Contribution	2,811		4,970
Total net revenue, Change in Contribution Percentage	15.00%		14.00%
Total segment profit	3,154	2,484	5,391	3,980
Total segment profit, Change in Contribution	670		1,411
Total segment profit, Change in Contribution Percentage	27.00%		35.00%
Total assets	98,016	96,125	98,016	96,125
Total segment assets, Change in Contribution	1,891
Total segment assets, Change in Contribution Percentage	2.00%
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Total net interest income	(25,547)	(26,132)	(50,622)	(50,681)
Total net interest income, Change in Contribution	585		59
Total net interest income, Change in Contribution Percentage	2.00%		0.00%
Total non-interest income	533	(3,615)	(1,519)	(4,986)
Total non-interest income, Change in Contribution	4,148		3,467
Non Interest Income Not Meaningful Variance	NM
Total non-interest income, Change in Contribution Percentage			70.00%
Total net revenue	(25,014)	(29,747)	(52,141)	(55,667)
Total net revenue, Change in Contribution	4,733		3,526
Total net revenue, Change in Contribution Percentage	16.00%		6.00%
Total segment profit	(16,912)	(17,272)	(34,518)	(34,998)
Total segment profit, Change in Contribution	360		480
Total segment profit, Change in Contribution Percentage	2.00%		1.00%
Total assets	(3,987,405)	(3,465,813)	(3,987,405)	(3,465,813)
Total segment assets, Change in Contribution	$ (521,592)
Total segment assets, Change in Contribution Percentage	(15.00%)