BUSINESS SEGMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Information
Interest income	$ 286,173	$ 238,423
Charge for funds used	(60,496)	(38,783)
Interest spread on funds used	225,677	199,640
Interest expense	(28,207)	(29,132)
Credit on funds provided	60,496	38,783
Interest spread on funds provided	32,289	9,651
Net interest income	257,966	209,291
Provision for loan losses	6,933	4,327	22,364
Depreciation, amortization and accretion	13,536	14,997
Goodwill	458,467	337,438	337,438
Segment pre-tax profit (loss)	111,690	106,510
Segment assets	27,401,026	23,101,955	24,730,068
Retail Banking
Segment Reporting Information
Interest income	98,724	82,839
Charge for funds used	(16,045)	(19,983)
Interest spread on funds used	82,679	62,856
Interest expense	(11,711)	(12,644)
Credit on funds provided	48,193	32,395
Interest spread on funds provided	36,482	19,751
Net interest income	119,161	82,607
Provision for loan losses	2,652	3,680
Depreciation, amortization and accretion	2,571	2,420
Goodwill	354,163	320,566
Segment pre-tax profit (loss)	50,084	18,927
Segment assets	7,877,996	6,665,478
Commercial Banking
Segment Reporting Information
Interest income	169,076	140,060
Charge for funds used	(21,328)	(28,073)
Interest spread on funds used	147,748	111,987
Interest expense	(3,280)	(4,378)
Credit on funds provided	8,436	3,623
Interest spread on funds provided	5,156	(755)
Net interest income	152,904	111,232
Provision for loan losses	4,281	647
Depreciation, amortization and accretion	(3,328)	(2,819)
Goodwill	104,304	16,872
Segment pre-tax profit (loss)	84,735	66,681
Segment assets	13,661,149	10,464,086
Other
Segment Reporting Information
Interest income	18,373	15,524
Charge for funds used	(23,123)	9,273
Interest spread on funds used	(4,750)	24,797
Interest expense	(13,216)	(12,110)
Credit on funds provided	3,867	2,765
Interest spread on funds provided	(9,349)	(9,345)
Net interest income	(14,099)	15,452
Depreciation, amortization and accretion	14,293	15,396
Segment pre-tax profit (loss)	(23,129)	20,902
Segment assets	$ 5,861,881	$ 5,972,391