NOTES PAYABLE - Summary of Lines of Credit (Detail) - 12 months ended Dec. 31, 2019 ¥ in Millions, $ in Millions	USD ($)	JPY (¥)
$100 million line of credit
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description	The rate quoted by the bank and agreed upon at the time of borrowing
Line of credit facility term	364 days
Line of credit facility, maximum borrowing capacity	$ 100
Line of credit facility, amount outstanding	$ 0
100.0 billion yen line of credit
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description	A rate per annum equal to (a) Tokyo interbank market rate (TIBOR) plus, the alternative applicable TIBOR margin during the availability period from the closing date to the commitment termination date or (b) the TIBOR rate offered by the agent to major banks in yen for the applicable period plus, the applicable alternative TIBOR margin during the term out period
Line of credit facility term	5 years
Line of credit facility, maximum borrowing capacity | ¥		¥ 100,000
Line of credit facility, amount outstanding | ¥		0
$1.0 billion line of credit
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description	A rate per annum equal to, at the Company's option, either, (a) the rate for Eurocurrency for deposits in the London interbank market for a period of one, two, three or six months (LIBOR) or (b) a base rate determined by reference to the highest of (1) the federal funds rate plus 1/2 of 1%, (2) the rate of interest in effect for such day as publicly announced from time to time by Mizuho as its “prime rate”, and (3) the LIBOR for a one month interest period in effect on such day (or if such day is not a business day, the immediately preceding business day) plus 1.00%, and in each case an applicable margin
Line of credit facility term	5 years
Line of credit facility, maximum borrowing capacity	$ 1,000
Line of credit facility, amount outstanding	$ 0
$50 million line of credit
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description	A rate per annum equal to, at the Parent Company's option, either (a) a eurocurrency rate determined by reference to the agent's LIBOR for the interest period relevant to such borrowing or (b) the base rate determined by reference to the greater of (i) the prime rate as determined by the agent, and (ii) the sum of 0.50% and the federal funds rate for such day
Line of credit facility, maximum borrowing capacity	$ 50
Line of credit facility, amount outstanding	$ 0
$250 million line of credit
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description	USD three-month LIBOR plus 75 basis points per annum
Line of credit facility term	364 days
Line of credit facility, maximum borrowing capacity	$ 250
Line of credit facility, amount outstanding	$ 0
Debt instrument, term	3 months
50.0 billion yen line of credit expiring April 2020
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description	Three-month TIBOR plus 70 basis points per annum
Line of credit facility term	364 days
Line of credit facility, maximum borrowing capacity | ¥		50,000
Line of credit facility, amount outstanding | ¥		0
Debt instrument, term	3 months
50.0 billion yen line of credit expiring November 2020
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description	Three-month TIBOR plus 70 basis points per annum
Line of credit facility term	364 days
Line of credit facility, maximum borrowing capacity | ¥		50,000
Line of credit facility, amount outstanding | ¥		¥ 0
Debt instrument, term	3 months
Lower Limit | 100.0 billion yen line of credit
Line of Credit Facility [Line Items]
Line of credit facility, commitment fee percentage	0.30%
Lower Limit | $1.0 billion line of credit
Line of Credit Facility [Line Items]
Line of credit facility, commitment fee percentage	0.085%
Upper Limit | $100 million line of credit
Line of Credit Facility [Line Items]
Debt instrument, term	3 months
Upper Limit | 100.0 billion yen line of credit
Line of Credit Facility [Line Items]
Line of credit facility, commitment fee percentage	0.50%
Upper Limit | $1.0 billion line of credit
Line of Credit Facility [Line Items]
Line of credit facility, commitment fee percentage	0.225%
Upper Limit | $50 million line of credit
Line of Credit Facility [Line Items]
Debt instrument, term	3 months