LOANS AND LEASES (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Composition of loan portfolio
Non-covered loans and leases	$ 3,839,215		$ 3,049,505
Covered loans	581,404		543,327
Total gross loans and leases	4,420,619		3,592,832	3,487,301
Unearned income	(933)		(2,535)
Total loans and leases, net of unearned income	4,419,686		3,590,297	3,484,703
Allowance for loan and lease losses:
Non-covered loans and leases	(63,246)		(65,899)
Covered loans	(27,397)		(26,069)
Total allowance for loans and lease losses	(90,643)	(94,519)	(91,968)	(103,524)	(110,577)	(116,588)
Total loans and leases, net	4,329,043		3,498,329	3,381,179
Non-PCI Loans
Composition of loan portfolio
Non-covered loans and leases	3,819,576		3,049,505
Covered loans	106,654		25,442
Total gross loans and leases	3,926,230		3,074,947	2,875,334
Unearned income	(933)		(2,535)
Total loans and leases, net of unearned income	3,925,297		3,072,412
Allowance for loan and lease losses:
Non-covered loans and leases	(63,246)		(65,899)
Total allowance for loans and lease losses	(63,246)	(65,216)	(65,899)	(72,061)	(74,767)	(85,313)
Total loans and leases, net	3,862,051		3,006,513
PCI Loans
Composition of loan portfolio
Non-covered loans and leases	19,639
Covered loans	474,750		517,885
Total gross loans and leases	494,389		517,885	611,967
Total loans and leases, net of unearned income	494,389		517,885
Allowance for loan and lease losses:
Covered loans	(27,397)		(26,069)
Total allowance for loans and lease losses	(27,397)	(29,303)	(26,069)	(31,463)	(35,810)	(31,275)
Total loans and leases, net	$ 466,992		$ 491,816