USE OF DERIVATIVE FINANCIAL INSTRUMENTS, OFFSETTING DISCLOSURES AND CHANGES IN OTHER COMPREHENSIVE INCOME BY COMPONENT - Schedule of Swap Agreements (Detail) (USD $)	9 Months Ended										9 Months Ended				12 Months Ended			3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 Interest Rate SWAP Currently-Paying Contracts [Member]	Sep. 30, 2013 Interest Rate SWAP Currently-Paying Contracts [Member] Fourth Quarter 2013 [Member]	Sep. 30, 2013 Interest Rate SWAP Currently-Paying Contracts [Member] First Quarter 2014 [Member]	Sep. 30, 2013 Interest Rate SWAP Currently-Paying Contracts [Member] Second Quarter 2014 [Member]	Sep. 30, 2013 Interest Rate SWAP Currently-Paying Contracts [Member] Third Quarter 2014 [Member]	Sep. 30, 2013 Interest Rate SWAP Currently-Paying Contracts [Member] Fourth Quarter 2014 [Member]	Sep. 30, 2013 Interest Rate SWAP Currently-Paying Contracts [Member] First Quarter 2015 [Member]	Sep. 30, 2013 Interest Rate SWAP Currently-Paying Contracts [Member] Second Quarter 2015 [Member]	Sep. 30, 2013 Interest Rate SWAP Currently-Paying Contracts [Member] Third Quarter 2015 [Member]	Sep. 30, 2013 Interest Rate SWAP Forward-Starting Contracts [Member]	Sep. 30, 2013 Interest Rate SWAP Forward-Starting Contracts [Member] Fourth Quarter 2015 [Member]	Sep. 30, 2013 Interest Rate SWAP Forward-Starting Contracts [Member] First Quarter 2016 [Member]	Sep. 30, 2013 Interest Rate SWAP Forward-Starting Contracts [Member] Second quarter 2016 [Member]	Dec. 31, 2010 Interest Rate Swap [Member]	Sep. 30, 2013 Interest Rate Swap [Member]	Dec. 31, 2012 Interest Rate Swap [Member]	Sep. 30, 2013 Interest Rate Swap New One [Member]	Sep. 30, 2013 Interest Rate Swap New Two [Member]	Sep. 30, 2013 Interest Rate Swap Expired One [Member]	Sep. 30, 2013 Interest Rate Swap Expired Two [Member]	Sep. 30, 2013 Repurchase Arrangements And Similar Borrowings [Member]	Dec. 31, 2012 Repurchase Arrangements And Similar Borrowings [Member]
Derivative Instruments And Hedging Activities [Line Items]
SWAP agreement notional amount during period															$ 100,000,000			$ 700,000,000	$ 2,600,000,000
SWAP agreement average interest rate during period (in hundredths)															4.09%			0.58%	0.50%
Swap agreement notional amount expiring during period																				300,000,000	2,100,000,000
SWAP agreement average interest rate expiring during period (in hundredths)																				0.87%	0.87%
Derivative, average remaining maturity (in months)	18 months	11 months									27 months
Notional Amount	7,100,000,000	3,800,000,000	800,000,000	200,000,000	400,000,000	200,000,000	500,000,000	1,100,000,000	200,000,000	400,000,000	3,300,000,000	1,200,000,000	1,700,000,000	400,000,000
Average Fixed Rate Payment Requirement (in hundredths)		0.57%	0.78%	0.60%	0.51%	0.51%	0.58%	0.50%	0.43%	0.47%	0.48%	0.45%	0.51%	0.45%
Payment term of LIBOR interest rate agreement															20 years			2 years	2 years
Derivative Instruments Unrealized Losses To Be Recognized	13,400,000
Accrued Interest																$ 6,400,000	$ 7,800,000					$ 2,400,000	$ 7,000,000