OFFESTTING OF ASSETS AND LIABILITIES - Offsetting of financial assets and liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Offsetting [Abstract]
Gross amount recognized of derivative asset	$ 6	$ 58
Gross amount of derivatives assets offset	0	0
Net asset amount of assets presented in the Statement of Financial Condition	6	58
Obligation to return Financial instrument, derivatives assets	6	58
Obligation to return Cash Collateral, derivative assets	0	0
Net derivative asset amount not offset	0	0
Gross amount recognized of derivative liabilities	33	3,965
Gross amount of derivative liabilities offset	0	0
Net derivative liability amount offset presented	33	3,965
Right to claim Financial instrument, derivatives liabilities	33	3,965
Right to claim Cash Collateral, derivatives liabilities	0	0
Net derivatives liability amount not offset	0	0
Gross amount recognized of repurchase agreements	600,000	600,000
Gross amount of repurchase agreements offset	0	0
Net repurchase agreements amount offset presented	600,000	600,000
Right to claim Financial instrument, repurchase agreements	600,000	600,000
Right to claim Cash Collateral, repurchase agreements	0	0
Net repurchase agreements amount not offset	0	0
Gross amount recognized of liabilities	600,033	603,965
Gross amount of liabilties offset	0	0
Net liabilities amount offset presented	600,033	603,965
Right to claim Financial instrument, liabilities	600,033	603,965
Right to claim Cash Collateral, liabilties	0	0
Net liability amount not offset	$ 0	$ 0