Schedule of Segment Financial Results (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net interest income	$ 97,360	$ 86,170	$ 187,718	$ 171,615
Provision for loan losses	5,000	5,000	8,000	9,500
Noninterest income	119,550	134,001	244,757	256,965
Noninterest expense	171,964	166,201	336,377	338,132
Income before income taxes	39,946	48,970	88,098	80,948
Income tax expense	9,732	14,298	24,119	22,863
Net Income	30,214	34,672	63,979	58,085
Average assets	17,413,000	15,618,000	17,124,000	16,065,000
Bank [Member]
Segment Reporting Information [Line Items]
Net interest income	82,758	72,481	158,085	143,602
Provision for loan losses	2,612	2,686	4,211	5,112
Noninterest income	47,548	56,024	99,099	103,458
Noninterest expense	107,293	100,788	207,861	208,337
Income before income taxes	20,401	25,031	45,112	33,611
Income tax expense	4,915	7,482	12,313	9,801
Net Income	15,486	17,549	32,799	23,810
Average assets	13,423,000	12,008,000	13,089,000	12,204,000
Payment Solutions [Member]
Segment Reporting Information [Line Items]
Net interest income	13,599	12,390	27,632	24,778
Provision for loan losses	2,388	2,314	3,789	4,388
Noninterest income	23,293	21,201	46,432	41,420
Noninterest expense	26,399	24,506	51,062	45,453
Income before income taxes	8,105	6,771	19,213	16,357
Income tax expense	2,046	1,931	5,373	4,524
Net Income	6,059	4,840	13,840	11,833
Average assets	2,980,000	2,148,000	3,031,000	2,023,000
Institutional Investment Management [Member]
Segment Reporting Information [Line Items]
Net interest income		(1)	1	(3)
Noninterest income	25,684	33,999	52,768	68,094
Noninterest expense	18,285	22,053	36,227	47,943
Income before income taxes	7,399	11,945	16,542	20,148
Income tax expense	1,785	3,389	4,511	5,532
Net Income	5,614	8,556	12,031	14,616
Average assets	70,000	69,000	72,000	71,000
Asset Servicing [Member]
Segment Reporting Information [Line Items]
Net interest income	1,003	1,300	2,000	3,238
Noninterest income	23,025	22,777	46,458	43,993
Noninterest expense	19,987	18,854	41,227	36,399
Income before income taxes	4,041	5,223	7,231	10,832
Income tax expense	986	1,496	1,922	3,006
Net Income	3,055	3,727	5,309	7,826
Average assets	$ 940,000	$ 1,393,000	$ 932,000	$ 1,767,000