Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
OPERATIONS:
Net interest income	$ 195,577	$ 198,031	$ 389,479	$ 309,379
Provision for Loan, Lease, and Other Losses	(15,253)	(7,309)	(29,790)	(17,256)
Noninterest Income	72,560	69,439	139,831	126,832
Other expenses	167,400	188,888	336,733	295,034
Net income	59,519	48,450	112,974	85,796
AVERAGES :
Assets	24,291,276	22,810,702	24,216,459	18,914,581
Total commercial
OPERATIONS:
Net interest income	106,924	114,557	211,987	182,947
Provision for Loan, Lease, and Other Losses	4,874	(2,120)	(167)	(6,886)
Noninterest Income	26,681	20,895	47,987	40,127
Other expenses	61,230	51,891	123,215	94,918
Net income	50,211	52,680	88,784	78,569
AVERAGES :
Assets	9,192,463	8,852,267	9,132,758	7,800,594
Retail
OPERATIONS:
Net interest income	94,879	95,904	188,129	145,658
Provision for Loan, Lease, and Other Losses	(14,905)	(2,101)	(17,522)	(6,174)
Noninterest Income	25,345	33,330	52,381	57,718
Other expenses	87,603	85,512	183,377	138,419
Net income	11,515	26,919	25,747	38,074
AVERAGES :
Assets	5,541,566	5,006,423	5,495,965	4,016,956
Wealth
OPERATIONS:
Net interest income	4,799	4,288	9,477	8,441
Provision for Loan, Lease, and Other Losses	(396)	42	351	166
Noninterest Income	14,052	12,821	27,516	21,131
Other expenses	12,370	13,832	25,097	24,006
Net income	3,955	2,027	7,504	3,379
AVERAGES :
Assets	258,845	263,454	250,279	250,206
Nonreportable segments and reconciling items
OPERATIONS:
Net interest income	(11,025)	(16,718)	(20,114)	(27,667)
Provision for Loan, Lease, and Other Losses	(4,826)	(3,130)	(11,750)	(4,030)
Noninterest Income	6,482	2,393	11,947	7,856
Other expenses	6,197	37,653	5,044	37,691
Net income	(6,162)	(33,176)	(9,061)	(34,226)
AVERAGES :
Assets	$ 9,298,402	$ 8,688,558	$ 9,337,457	$ 6,846,825