STOCK AWARD PLANS - Employee Stock Purchase Plan Activity (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased by employees (shares)	75,029
Aggregate cost to employees	$ 6,086
Expense recognized by the company	23,989	$ 11,397
Company expense on ESPP discount
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized by the company	$ 1,074	$ 981

Number of shares issued during the period as a result of an employee stock purchase plan.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration