DESCRIPTION OF BUSINESS (Details) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Mar. 31, 2015 USD ($) $ / shares shares	Oct. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) state segment $ / shares	Dec. 31, 2014 USD ($) $ / shares	Sep. 30, 2014 $ / shares
DESCRIPTION OF BUSINESS
Number of pharmacy locations (in locations)			16
Number of states with call center locations (in states) | state			50
Number of Reportable Segments | segment			1
Initial Public Offering [Line Items]
Proceeds from public offering, net of transaction costs			$ 187,988	$ 130,440
Number of newly authorized shares issued upon conversion (in shares) | shares		1
Common shares, par value (in dollars per share) | $ / shares		$ 0	$ 0	$ 0	$ 0
Initial Public Offering
Initial Public Offering [Line Items]
Number of shares of common stock sold (in shares) | shares		15,333,333
Initial public offering price (in dollars per share) | $ / shares		$ 13.00
Number of shares sold by the Company (in shares) | shares		11,000,000
Number of shares of stock sold by the existing shareholders (in shares) | shares		4,333,333
Net proceeds from initial public offering		$ 130,440
Underwriting discounts and commissions		9,652
Other offering expenses		2,908
Amount of borrowings repaid under the revolving line of credit with IPO proceeds		80,458
Existing indebtedness to certain current or former shareholders and employees		(19,824)
Borrowings under the revolving line of credit repaid		$ (60,634)
Follow-On Public Offering
Initial Public Offering [Line Items]
Number of shares of common stock sold (in shares) | shares	9,821,125
Initial public offering price (in dollars per share) | $ / shares	$ 29.00
Number of shares sold by the Company (in shares) | shares	6,821,125
Number of shares of stock sold by the existing shareholders (in shares) | shares	3,000,000
Underwriting discounts and commissions	$ 9,141
Other offering expenses	685
Proceeds from public offering, net of transaction costs	187,988
Net proceeds used to repurchase stock options	$ 36,298