NOTES PAYABLE, FINANCE LEASES, AND COMMERCIAL BANK FINANCING - Bank Credit Agreements (Details)		6 Months Ended
Apr. 01, 2021 USD ($)	Jun. 30, 2021 USD ($)
Debt Instrument [Line Items]
Borrowings under revolving credit facility exceed total commitments (as a percent)		35.00%
STG Revolving Credit Facility
Debt Instrument [Line Items]
First lien leverage ratio		4.5
Borrowings outstanding		$ 0
DSG Revolving Credit Facility
Debt Instrument [Line Items]
First lien leverage ratio		6.25
Borrowings outstanding		$ 0
STG Term Loan Facility \| Term Loan B-3
Debt Instrument [Line Items]
Aggregate principal amount	$ 740,000,000
Issuance of debt discount	$ 4,000,000
Outstanding balance		$ 735,000,000
STG Term Loan Facility \| Term Loan B-3 \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	3.00%

Debt Instrument, Covenant, First Lien Leverage Ratio Test, Borrowings Exceed Total Commitments, Percent

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Debt Instrument, Covenant, Required Prepayment, First Lien Leverage Ratio

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Face (par) amount of debt instrument at time of issuance.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after accumulated amortization, of debt discount.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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