SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE - Schedule of Repurchase Agreement Maturity (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Repurchase Agreement [Line Items]
Securities Sold Under Agreements To Repurchase	$ 900,000	[1]	$ 900,000
Callable Repurchase Agreements [Member]
Repurchase Agreement [Line Items]
Securities Sold Under Agreements To Repurchase	800,000
Variable Rate [Member]
Repurchase Agreement [Line Items]
Securities Sold Under Agreements To Repurchase	$ 600,000

[1] As of September 30, 2014, includes $800 million with an average rate of 3.07% that lenders have the right to call before their contractual maturities at various dates beginning on October 9, 2014. Subsequent to September 30, 2014, no lender has exercised its call option on repurchase agreements. In addition, $600 million of the $900 million is tied to variable rates.