USE OF DERIVATIVE FINANCIAL INSTRUMENTS, OFFSETTING DISCLOSURES AND CHANGES IN OTHER COMPREHENSIVE INCOME BY COMPONENT - Schedule of Swap Agreements (Detail) (USD $)	3 Months Ended													12 Months Ended			3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014 Interest Rate SWAP Currently-Paying Contracts [Member]	Mar. 31, 2014 Interest Rate SWAP Currently-Paying Contracts [Member] Second Quarter 2014 [Member]	Mar. 31, 2014 Interest Rate SWAP Currently-Paying Contracts [Member] Third Quarter 2014 [Member]	Mar. 31, 2014 Interest Rate SWAP Currently-Paying Contracts [Member] Fourth Quarter 2014 [Member]	Mar. 31, 2014 Interest Rate SWAP Currently-Paying Contracts [Member] First Quarter 2015 [Member]	Mar. 31, 2014 Interest Rate SWAP Currently-Paying Contracts [Member] Second Quarter 2015 [Member]	Mar. 31, 2014 Interest Rate SWAP Currently-Paying Contracts [Member] Third Quarter 2015 [Member]	Mar. 31, 2014 Interest Rate SWAP Currently-Paying Contracts [Member] Fourth Quarter 2015 [Member]	Mar. 31, 2014 Interest Rate SWAP Currently-Paying Contracts [Member] First Quarter 2016 [Member]	Mar. 31, 2014 Interest Rate SWAP Forward-Starting Contracts [Member]	Mar. 31, 2014 Interest Rate SWAP Forward-Starting Contracts [Member] Second quarter 2016 [Member]	Mar. 31, 2014 Interest Rate SWAP Forward-Starting Contracts [Member] Third Quarter 2016 [Member]	Dec. 31, 2010 Interest Rate Swap [Member]	Mar. 31, 2014 Interest Rate Swap [Member]	Dec. 31, 2013 Interest Rate Swap [Member]	Mar. 31, 2014 Interest Rate Swap New One [Member]	Mar. 31, 2014 Interest Rate Swap Expired One [Member]	Mar. 31, 2014 Interest Rate Swap Expired Two [Member]	Mar. 31, 2014 Repurchase Arrangements And Similar Borrowings [Member]	Dec. 31, 2013 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
SWAP agreement average interest rate during period (in hundredths)														4.09%			0.52%
Swap agreement notional amount expiring during period																		200,000,000	1,700,000,000
SWAP agreement average interest rate expiring during period (in hundredths)																		0.60%	0.51%
Notional Amount	7,200,000,000	5,700,000,000	400,000,000	200,000,000	500,000,000	1,100,000,000	200,000,000	400,000,000	1,200,000,000	1,700,000,000	1,500,000,000	1,100,000,000	400,000,000
Average Fixed Rate Payment Requirement (in hundredths)		0.50%	0.51%	0.51%	0.58%	0.50%	0.43%	0.47%	0.45%	0.51%	0.49%	0.47%	0.54%
Payment term of LIBOR interest rate agreement														20 years			2 years
Derivative Instruments Unrealized Losses To Be Recognized	17,600,000
Accrued Interest															$ 7,600,000	$ 5,500,000				$ 3,400,000	$ 4,700,000