NOTES PAYABLE AND LEASE OBLIGATIONS - Summary of Lines of Credit (Details) - 9 months ended Sep. 30, 2020 ¥ in Millions, $ in Millions	JPY (¥)	USD ($)
$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		$ 100.0
Line of credit facility, amount outstanding		0.0
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 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) LIBOR adjusted for certain costs 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 for such day announced by Mizuho Bank, Ltd. as its prime rate, or (3) the eurocurrency rate for an interest period of one month plus 1.00%, in each case plus an applicable margin
Line of credit facility term	5 years
Line of credit facility, maximum borrowing capacity		1,000.0
Line of credit facility, amount outstanding		0.0
$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		50.0
Line of credit facility, amount outstanding		0.0
$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		250.0
Line of credit facility, amount outstanding		0.0
Debt instrument, term	3 months
50.0 billion yen line of credit expiring April 2021
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
$25 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		25.0
Line of credit facility, amount outstanding		0.0
Debt instrument, term	3 months
$15 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		15.0
Line of credit facility, amount outstanding		0.0
Debt instrument, term	3 months
$300 thousand 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		0.3
Line of credit facility, amount outstanding		$ 0.0
Debt instrument, term	3 months
500 million yen line of credit
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	A rate per annum equal to the short-term prime lending rates of banks appearing on the website for the Bank of Japan on the first day of the applicable period
Line of credit facility term	364 days
Line of credit facility, maximum borrowing capacity | ¥	¥ 500
Line of credit facility, amount outstanding | ¥	¥ 350
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 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 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