RECLASSIFICATION FROM ACCUMULATED OTHER COMPREHENSIVE INCOME INTO NET INCOME - Summary of Amounts Reclassified out of Accumulated Other Comprehensive Income into Net Income (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Jan. 31, 2014	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other-than-temporary impairment (OTTI) on securities	$ 1,000	$ 2,494	$ 1,574	$ 649	$ 1,071	$ 448	$ 0	$ 615	$ 328	$ 5,788	$ 1,391	$ 4,993
Total reclassifications		$ (99,052)	$ (61,755)	$ (79,277)	$ (41,798)	$ (50,928)	$ (152,098)	$ (182,208)	$ (56,865)	(281,882)	(442,099)	(265,623)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on settlement of securities										(13,096)	(65,701)	(52,657)
Other-than-temporary impairment (OTTI) on securities										5,788	1,391	4,993
Total reclassifications										$ (7,308)	$ (64,310)	$ (47,664)