OFFSETTING OF ASSETS AND LIABILITIES - Schedule of Derivative Instruments by Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Offsetting of Assets
Gross Amounts of Recognized Assets, Derivatives not subject to a master netting arrangement	$ 798,434	$ 375,829
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	798,434	375,829
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments, not subject to a master netting arrangement	263,245	70,322
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Received	255,776	99,199
Net Amount	279,413	206,308
Free-Standing derivatives
Offsetting of Assets
Gross Amounts of Recognized Assets, Derivatives subject to a master netting arrangement	630,474	263,349
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	630,474	263,349
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments, subject to a master netting arrangement	263,245	70,322
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Received	255,776	99,199
Net Amount	111,453	93,828
Total derivatives, subject to a master netting arrangement or similar arrangement
Offsetting of Assets
Gross Amounts of Recognized Assets, Derivatives subject to a master netting arrangement	630,474	263,349
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	630,474	263,349
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments, subject to a master netting arrangement	263,245	70,322
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Received	255,776	99,199
Net Amount	111,453	93,828
Embedded derivative - Modco reinsurance treaties
Offsetting of Assets
Gross Amounts of Recognized Assets, Derivatives not subject to a master netting arrangement	30,600	7,072
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	30,600	7,072
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments, not subject to a master netting arrangement	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Received	0	0
Net Amount	30,600	7,072
Embedded derivative - GLWB
Offsetting of Assets
Gross Amounts of Recognized Assets, Derivatives not subject to a master netting arrangement	137,360	105,272
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	137,360	105,272
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments, not subject to a master netting arrangement	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Received	0	0
Net Amount	137,360	105,272
Other
Offsetting of Assets
Gross Amounts of Recognized Assets, Derivatives not subject to a master netting arrangement	0	136
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	0	136
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments, not subject to a master netting arrangement	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Received	0	0
Net Amount	0	136
Total derivatives, not subject to a master netting arrangement or similar arrangement
Offsetting of Assets
Gross Amounts of Recognized Assets, Derivatives not subject to a master netting arrangement	167,960	112,480
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	167,960	112,480
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments, not subject to a master netting arrangement	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Received	0	0
Net Amount	$ 167,960	$ 112,480

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and elected not to be offset.

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