COMPANY-SPONSORED EMPLOYEE BENEFIT PLANS - Reconciliation of the Changes in the Plans' Benefit Obligations and Fair Value of Plan Assets (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Benefit Obligations:
Actuarial (gain)/loss	$ (3,174)	$ 4,441
Fair Value of Plan Assets:
Fair value of plan assets at beginning of year	43,448
Fair value of plan assets at end of year	$ 40,864	$ 43,448

Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

+ References

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