USE OF DERIVATIVE FINANCIAL INSTRUMENTS, OFFSETTING DISCLOSURES AND CHANGES IN OTHER COMPREHENSIVE INCOME BY COMPONENT - Changes in AOCI (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accumulated other comprehensive income (loss) [Line Items]
Beginning Balance	$ 227,902		$ 219,143
Other comprehensive income (loss) before reclassifications	3,494		7,531
Amount of loss reclassified from Accumulated other comprehensive income related to the effective portion of active positions	5,384	4,416	10,106	9,850
Other comprehensive income (loss)	8,878	(46,853)	17,637	(46,645)
Ending Balance	236,780		236,780
Gains and Losses on Cash Flow Hedges [Member]
Accumulated other comprehensive income (loss) [Line Items]
Beginning Balance	(14,239)		(6,305)
Other comprehensive income (loss) before reclassifications	(12,998)		(25,654)
Amount of loss reclassified from Accumulated other comprehensive income related to the effective portion of active positions	5,384		10,106
Other comprehensive income (loss)	(7,614)		(15,548)
Ending Balance	(21,853)		(21,853)
Unrealized Gains and Losses on Available-for-sale Securities [Member]
Accumulated other comprehensive income (loss) [Line Items]
Beginning Balance	242,141		225,448
Other comprehensive income (loss) before reclassifications	16,492		33,185
Amount of loss reclassified from Accumulated other comprehensive income related to the effective portion of active positions	0		0
Other comprehensive income (loss)	16,492		33,185
Ending Balance	$ 258,633		$ 258,633