LONG-TERM DEBT - Credit Facility (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 29, 2017	Dec. 31, 2016	Dec. 31, 2015
Long-term debt
Amount outstanding	$ 24,500,000		$ 34,300,000
Repurchase of common stock, authorized amount		$ 10,000,000		$ 10,000,000
Revolving Credit Facility
Long-term debt
Line of credit facility, extension term	1 year
Line of credit facility, maximum borrowing capacity	$ 75,000,000
Line of credit facility, maximum borrowing capacity, after possible increase	125,000,000
Line of credit facility, current borrowing capacity	$ 50,500,000
Line of credit facility unused portion of the borrowing capacity fee percentage condition	50.00%
Amount outstanding	$ 24,500,000
Revolving Credit Facility | Minimum
Long-term debt
Line of credit facility, basis points added to LIBOR interest rate	1.35%
Line of credit facility, commitment fee percentage on unused portion of the borrowing capacity	0.20%
Revolving Credit Facility | Maximum
Long-term debt
Line of credit facility, commitment fee percentage on unused portion of the borrowing capacity	0.25%
Revolving Credit Facility | LIBOR | Maximum
Long-term debt
Line of credit facility, basis points added to LIBOR interest rate	2.25%
New Repurchase Program [Member]
Long-term debt
Repurchase of common stock, authorized amount	$ 10,000,000