SIGNIFICANT ACCOUNTING POLICIES - Schedule of Deferred Income (Details) $ in Millions	Dec. 31, 2020 USD ($)
Deferred Policy Acquisition Cost [Line Items]
Sales inducement assets and unearned revenue liability	$ 106
As Previously Reported
Deferred Policy Acquisition Cost [Line Items]
Sales inducement assets and unearned revenue liability	69
Effect of Modified Retrospective Application Accounting Standards Update 2018-12
Deferred Policy Acquisition Cost [Line Items]
Sales inducement assets and unearned revenue liability	37
Variable Universal Life | Life Insurance & Employee Benefits Products
Deferred Policy Acquisition Cost [Line Items]
Sales inducement assets and unearned revenue liability	83
Variable Universal Life | Life Insurance & Employee Benefits Products | As Previously Reported
Deferred Policy Acquisition Cost [Line Items]
Sales inducement assets and unearned revenue liability	55
Variable Universal Life | Life Insurance & Employee Benefits Products | Effect of Modified Retrospective Application Accounting Standards Update 2018-12
Deferred Policy Acquisition Cost [Line Items]
Sales inducement assets and unearned revenue liability	28
Indexed Universal Life | Life Insurance & Employee Benefits Products
Deferred Policy Acquisition Cost [Line Items]
Sales inducement assets and unearned revenue liability	23
Indexed Universal Life | Life Insurance & Employee Benefits Products | As Previously Reported
Deferred Policy Acquisition Cost [Line Items]
Sales inducement assets and unearned revenue liability	14
Indexed Universal Life | Life Insurance & Employee Benefits Products | Effect of Modified Retrospective Application Accounting Standards Update 2018-12
Deferred Policy Acquisition Cost [Line Items]
Sales inducement assets and unearned revenue liability	$ 9