EARNINGS PER SHARE - Antidilutive Securities (Details) - Common Stock [Member] - shares	3 Months Ended		6 Months Ended
	Jun. 27, 2018	Jun. 28, 2017	Jun. 27, 2018	Jun. 28, 2017
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares (in shares)	0	6,258	0	6,258
Performance stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares (in shares)	60,437	84,755	60,437	84,755
Shares of Class B common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares (in shares)	8,924,592	10,770,992	8,924,592	10,770,992