SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended			36 Months Ended
	Mar. 31, 2010	Dec. 31, 2012 branchlocations	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 entities branchlocations
Number of branches (branches)		414			414
Maximum period of fair value refinement after transaction closing date		1 year	1 year
Minimum sustained performance for non-accrual status loans to accrue interest			6 years
Number of entities assets were acquired and liabilities were assumed					6
Impaired loans and leases, baseline for meaurement		$ 500	$ 1,000		$ 500
Impaired loans and leases, baseline for meaurement, classified as TDRs		100			100
Securities sold under repurchase agreements		111,907	172,275		111,907
Average shares outstanding (in shares)		10,244,472	10,376,445	10,434,453
Loans sold		581,911	509,647	583,750
Allowance for loan and lease losses, period increase (decrease)		(94,011)	(189,898)	(88,717)
Adoption of change in accounting for QSPE	$ (304)	$ 0	$ 0	$ (304)
Common Class A [Member]
Votes per share of common stock		1
Common Class B [Member]
Votes per share of common stock		16
Building [Member] | Minimum [Member]
Useful life		25 years
Building [Member] | Maximum [Member]
Useful life		40 years
Furniture and Fixtures [Member] | Minimum [Member]
Useful life		3 years
Furniture and Fixtures [Member] | Maximum [Member]
Useful life		10 years
Software [Member] | Minimum [Member]
Useful life			3 years
Software [Member] | Maximum [Member]
Useful life			10 years
Equipment [Member] | Minimum [Member]
Useful life			3 years
Equipment [Member] | Maximum [Member]
Useful life			10 years