Schedule of Segment Financial Results (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Net interest income	$ 85,445	$ 79,483
Provision for loan losses	4,500	2,000
Noninterest income	122,964	121,016
Noninterest expense	172,241	150,378
Income before income taxes	31,668	48,121
Income tax expense	8,255	13,180
Net income	23,413	34,941
Average assets	16,504,000	14,783,000
Bank [Member]
Segment Reporting Information [Line Items]
Net interest income	71,121	67,260
Provision for loan losses	2,426	309
Noninterest income	47,420	52,748
Noninterest expense	107,753	91,536
Income before income taxes	8,362	28,163
Income tax expense	1,942	7,705
Net income	6,420	20,458
Average assets	12,299,000	11,306,000
Payment Solutions [Member]
Segment Reporting Information [Line Items]
Net interest income	12,388	11,548
Provision for loan losses	2,074	1,691
Noninterest income	20,235	19,437
Noninterest expense	21,015	20,117
Income before income taxes	9,534	9,177
Income tax expense	2,609	2,534
Net income	6,925	6,643
Average assets	1,952,000	1,698,000
Institutional Investment Management [Member]
Segment Reporting Information [Line Items]
Net interest income	(2)
Provision for loan losses
Noninterest income	34,095	28,552
Noninterest expense	25,894	18,845
Income before income taxes	8,199	9,707
Income tax expense	2,184	2,667
Net income	6,015	7,040
Average assets	74,000	78,000
Asset Servicing [Member]
Segment Reporting Information [Line Items]
Net interest income	1,938	675
Provision for loan losses
Noninterest income	21,214	20,279
Noninterest expense	17,579	19,880
Income before income taxes	5,573	1,074
Income tax expense	1,520	274
Net income	4,053	800
Average assets	$ 2,179,000	$ 1,701,000