SUBSEQUENT EVENTS Additional Information (Detail) - 1 months ended Oct. 31, 2018 - Subsequent events $ in Millions, ¥ in Billions	USD ($) series	JPY (¥) series
Subsequent Event [Line Items]
Number of Series of Senior Notes Issued Through a U.S. Public Debt Offering | series	3	3
Senior notes
Subsequent Event [Line Items]
Debt instrument, principal amount		¥ 53.4
1.159% senior notes due October 2030
Subsequent Event [Line Items]
Debt instrument, principal amount		¥ 29.3
Debt instrument, interest rate	1.159%	1.159%
Debt instrument, term	12 years
1.488% senior notes due October 2033
Subsequent Event [Line Items]
Debt instrument, principal amount		¥ 15.2
Debt instrument, interest rate	1.488%	1.488%
Debt instrument, term	15 years
1.750% senior notes due October 2038
Subsequent Event [Line Items]
Debt instrument, principal amount		¥ 8.9
Debt instrument, interest rate	1.75%	1.75%
Debt instrument, term	20 years
4.750% senior notes due January 2049
Subsequent Event [Line Items]
Debt instrument, principal amount | $	$ 550
Debt instrument, interest rate	4.75%	4.75%
Debt Instrument, Redemption, Description	These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the yield to maturity for a United States Treasury security with a maturity comparable to the remaining term of the notes, plus 25 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date.
Debt instrument, term	30 years