PENSION PLAN (Details) - Pension Plan $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
PENSION PLAN
Fair value of plan assets	$ 1.1
Percentage of tax on assets to be paid upon reversion	45.00%
Percentage of exercise tax	20.00%
Waltham, Inc.
PENSION PLAN
Fair value of plan assets	$ 2.3
Fair value of plan obligation	3.0
Employer contributions	0.1
Waltham, Inc. | Unfunded Status
PENSION PLAN
Unfunded status amount	$ 0.7