STOCK BASED COMPENSATION - Balances of stock-based compensation plans (Details) shares in Thousands	3 Months Ended
	Mar. 28, 2020 $ / shares shares
Stock Options
Number of Options
Balance at the beginning (in shares) | shares	1,618
Granted (in shares) | shares	0
Exercised/released (in shares) | shares	(62)
Forfeited/expired (in shares) | shares	(81)
Balance at the end (in shares) | shares	1,475
Weighted Average Exercise Price
Balance at the beginning (in dollars per share) | $ / shares	$ 16.44
Granted (in dollars per share) | $ / shares	0
Exercised/released (in dollars per share) | $ / shares	2.64
Forfeited/expired (in dollars per share) | $ / shares	22.06
Balance at the end (in dollars per share) | $ / shares	$ 16.71
Restricted Stock Units
Number of Shares
Balance at the beginning (in shares) | shares	296
Granted (in shares) | shares	501
Exercised/released (in shares) | shares	(81)
Forfeited/expired (in shares) | shares	(37)
Balance at the end (in shares) | shares	679
Weighted Average Grant Date Fair Value
Balance at the beginning (in dollars per share) | $ / shares	$ 23.85
Granted (in dollars per share) | $ / shares	32.70
Exercised/released (in dollars per share) | $ / shares	22.87
Forfeited/expired (in dollars per share) | $ / shares	30.16
Balance at the end (in dollars per share) | $ / shares	$ 30.15
Deferred Stock Units
Number of Shares
Balance at the beginning (in shares) | shares	23
Granted (in shares) | shares	1
Exercised/released (in shares) | shares	0
Forfeited/expired (in shares) | shares	0
Balance at the end (in shares) | shares	24
Weighted Average Grant Date Fair Value
Balance at the beginning (in dollars per share) | $ / shares	$ 20.39
Granted (in dollars per share) | $ / shares	37.39
Exercised/released (in dollars per share) | $ / shares	0
Forfeited/expired (in dollars per share) | $ / shares	0
Balance at the end (in dollars per share) | $ / shares	$ 21.10