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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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EQUITY COMPENSATION PLANS - Narrative (Details) - USD ($)		12 Months Ended
	Apr. 27, 2012	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense		$ 3,500,000	$ 2,900,000	$ 2,100,000
Compensation costs capitalized as part of inventory		0	0	0
Tax benefit from compensation expense		500,000	200,000	1,300,000
Total intrinsic value for options exercised		800,000	400,000	1,400,000
Cash received from exercise of stock option		2,500,000	400,000	900,000
Intrinsic value of exercisable stock options		1,300,000
Intrinsic value of unvested stock options		$ 3,600,000
Stock repurchased during period (shares)		11,329
Aggregate purchase price of shares repurchased		$ 300,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of stock awards		10 years
Realized income tax benefit		$ 200,000	$ 100,000	$ 300,000
Total unrecognized compensation cost		$ 1,900,000
Weighted-average expected amortization period		2 years 6 months
Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock awards		3 years
Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock awards		4 years
Time-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost		$ 2,100,000
Weighted-average expected amortization period		1 year 9 months 18 days
Intrinsic value of unvested restricted shares		$ 5,300,000
Time-Based Restricted Stock Units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock awards		2 years
Time-Based Restricted Stock Units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock awards		3 years
Performance-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock awards		3 years
Total unrecognized compensation cost		$ 1,600,000
Weighted-average expected amortization period		2 years 1 month 6 days
Intrinsic value of unvested restricted shares		$ 4,000,000.0
2012 Stock Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share options and restricted shares authorized (shares)	3,000,000.0
Number of additional shares authorized (shares)	19,720