DEBT (Details - Revolving Credit Facility)			9 Months Ended
	Jul. 21, 2020 USD ($)	Dec. 10, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Oct. 26, 2018 USD ($)
Line of Credit Facility [Line Items]
Current maturities of debt			$ 0		$ 75,000,000.0
Weighted average interest rate					3.01%
Potential additional borrowing capacity		$ 185,000,000.0
Letters of credit outstanding			200,000		$ 200,000
Ratio of Debt to EBITDA Step-Down		4.0
Ratio of Debt to EBITDA Increase		0.5
Debt Instrument, Unused Borrowing Capacity, Fee			1,100,000	$ 500,000
Amortization of debt issuance costs			2,241,000	1,463,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 500,000,000.0				$ 350,000,000.0
Debt term		5 years
Revolving Credit Facility, collateral, percent of assets		100.00%
Revolving Credit Facility, collateral, percent of equity		100.00%
Revolving Credit Facility, letter of credit fronting fee percentage		0.125%
Fees and expense paid to lenders at closing	$ 1,100,000					$ 2,800,000
Line of Credit Facility, Collateral, Percent of Domestic Subsidiaries Equity		100.00%
Line of Credit Facility, Collateral, Percent of Voting Equity		66.00%
Line of Credit Facility, Collateral, Percent of Non-Voting Equity		100.00%
Swingline Facility [Member]
Line of Credit Facility [Line Items]
Covenant amount		$ 10,000,000.0
Letters of Credit [Member]
Line of Credit Facility [Line Items]
Covenant amount		$ 10,000,000.0
Fed Funds Effective Rate Overnight Index Swap Rate [Member] | Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving Credit Facility, basis spread on variable rate		0.50%
LIBOR | Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving Credit Facility, basis spread on variable rate		1.00%
Interest Expense, Debt			1,300,000	4,200,000
Minimum | Revolving Credit Facility
Line of Credit Facility [Line Items]
Unused capacity, commitment fee percentage		0.25%
Revolving Credit Facility, letter of credit participation fee percentage		1.25%
Minimum | LIBOR | Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving Credit Facility, basis spread on variable rate		1.25%
Minimum | Base Rate | Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving Credit Facility, basis spread on variable rate		0.25%
Maximum
Line of Credit Facility [Line Items]
Ratio of Debt to EBITDA to Increase Revolving Commitment		2.50
Ratio of Debt to EBITDA		4.5
Maximum | Revolving Credit Facility
Line of Credit Facility [Line Items]
Unused capacity, commitment fee percentage		0.45%
Revolving Credit Facility, letter of credit participation fee percentage		2.00%
Maximum | LIBOR | Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving Credit Facility, basis spread on variable rate		2.00%
Maximum | Base Rate | Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving Credit Facility, basis spread on variable rate		1.00%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Interest Expense, Debt			3,200,000	5,100,000
Amortization of debt issuance costs			$ 800,000	$ 400,000
Revolving Credit Facility, 31 Day Borrowing | Revolving Credit Facility
Line of Credit Facility [Line Items]
Current maturities of debt					50,000,000.0
Revolving Credit Facility, 32 Day Borrowing | Revolving Credit Facility
Line of Credit Facility [Line Items]
Current maturities of debt					$ 25,000,000.0
Line of Credit [Member] | Revolving Credit Facility
Line of Credit Facility [Line Items]
Covenant amount	$ 200,000,000.0
Debt Instrument, Floor Interest Rate	0.75%
Unused capacity, commitment fee percentage	0.50%
Line of Credit [Member] | LIBOR | Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving Credit Facility, basis spread on variable rate	2.25%
Line of Credit [Member] | Base Rate | Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving Credit Facility, basis spread on variable rate	1.25%