INCOME TAXES (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
INCOME TAXES
Net deferred tax assets	$ 185,713,000				$ 201,883,000				$ 185,713,000	$ 201,883,000
Tax credits generated from investments in affordable housing partnerships and other investments									18,700,000	11,100,000	12,400,000
Current income tax expense (benefit):
Federal									148,572,000	(86,157,000)	9,942,000
State									2,316,000	34,760,000	69,026,000
Foreign									5,704,000
Total current income tax expense (benefit)									156,592,000	(51,397,000)	78,968,000
Deferred income tax (benefit) expense:
Federal									(38,749,000)	193,834,000	55,083,000
State									26,099,000	(7,706,000)	(48,273,000)
Foreign										3,369,000	5,567,000
Total deferred income tax (benefit) expense									(12,650,000)	189,497,000	12,377,000
Provision (benefit) for income taxes	$ 36,300,000	$ 34,093,000	$ 33,837,000	$ 39,712,000	$ 37,133,000	$ 35,253,000	$ 35,205,000	$ 30,509,000	$ 143,942,000	$ 138,100,000	$ 91,345,000
Difference between the effective tax rate implicit in the consolidated financial statements and the statutory federal income tax rate
Federal income tax provision at statutory rate (as a percent)									35.00%	35.00%	35.00%
State franchise taxes, net of federal tax effect (as a percent)									4.30%	4.30%	5.30%
Tax credits (as a percent)									(5.30%)	(2.70%)	(4.80%)
Other, net (as a percent)									(0.20%)	(0.60%)	0.20%
Effective income tax rate (as a percent)									33.80%	36.00%	35.70%