STOCKHOLDER'S EQUITY (Details) $ / shares in Units, $ in Thousands			1 Months Ended		4 Months Ended	11 Months Ended	12 Months Ended
	Feb. 04, 2015 USD ($) board_of_director_class Vote / shares $ / shares shares	Dec. 15, 2014	Dec. 30, 2015 $ / shares shares	Aug. 31, 2015 $ / shares shares	Dec. 30, 2015 $ / shares shares	Dec. 30, 2015 $ / shares shares	Dec. 30, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 25, 2013 USD ($)
Class of Stock [Line Items]
Common stock, shares authorized								100
Common stock par value (in dollars per share) | $ / shares								$ 0.01
Preferred stock, shares authorized	10,000,000		10,000,000		10,000,000	10,000,000	10,000,000
Number of classes of directors | board_of_director_class	3
Board of directors, term	3 years
Number of votes per share | Vote / shares	1
LLC interests acquired	5,968,841				2,848,035		6,003,308
Member distribution threshold, percentage		27.30%
Member distributions | $							$ 11,125	$ 27,070	$ 0
Class A Common Stock
Class of Stock [Line Items]
Common stock, shares authorized	200,000,000		200,000,000		200,000,000	200,000,000	200,000,000
Common stock par value (in dollars per share) | $ / shares	$ 0.001		$ 0.001		$ 0.001	$ 0.001	$ 0.001
Ratio of common stock to limited liability company interest	1
Class B Common Stock
Class of Stock [Line Items]
Common stock, shares authorized	35,000,000		35,000,000		35,000,000	35,000,000	35,000,000
Common stock par value (in dollars per share) | $ / shares	$ 0.001		$ 0.001		$ 0.001	$ 0.001	$ 0.001
Ratio of common stock to limited liability company interest	1
Secondary offering
Class of Stock [Line Items]
LLC interests acquired				3,155,273
USC Merger
Class of Stock [Line Items]
LLC interests acquired			1,727,804
Common stock | Class A Common Stock
Class of Stock [Line Items]
Shares issued during the period	5,968,841					5,750,000
Redemptions (shares)					2,848,035
Common stock | Class B Common Stock
Class of Stock [Line Items]
Shares issued during the period	30,160,694
Effect of redemption (shares)	5,968,841				2,848,035
Common stock | IPO | Class A Common Stock
Class of Stock [Line Items]
Shares issued during the period	5,750,000
Proceeds of issuance of initial public offering net of underwriting discounts and commissions | $	$ 112,298
Shares issued, share price (in dollars per share) | $ / shares	$ 21
Common stock | Over-allotment option | Class A Common Stock
Class of Stock [Line Items]
Shares issued during the period	750,000
Common stock | Secondary offering | Class A Common Stock
Class of Stock [Line Items]
Shares issued, share price (in dollars per share) | $ / shares				$ 60
Total conversion of units (shares)				4,000,000
Conversion of units from former equity owners (shares)				844,727
Redemptions (shares)				3,155,273
Common stock | Secondary offering | Class B Common Stock
Class of Stock [Line Items]
Effect of redemption (shares)				3,155,273
Common stock | USC Merger | Class A Common Stock
Class of Stock [Line Items]
Shares issued during the period			1,727,804
Redemptions (shares)						1,727,804
Common stock | USC Merger | Class B Common Stock
Class of Stock [Line Items]
Redemptions (shares)						(1,727,804)
Effect of redemption (shares)			1,727,804
Limited Liability Company
Class of Stock [Line Items]
Number of units redeemed (shares)					2,848,035		6,003,308
Limited Liability Company | Secondary offering
Class of Stock [Line Items]
Number of units redeemed (shares)				3,155,273