DEBT (Details)			12 Months Ended
	Aug. 28, 2015 USD ($)	Jun. 15, 2011 USD ($) $ / shares	Dec. 31, 2015 USD ($) shares	Sep. 30, 2016 USD ($)	Jun. 10, 2015 convertible_debt_instrument
2016 Notes:
Carrying amount of liability			$ 218,240,000	$ 225,248,000
Revolving Credit Facility
2016 Notes:
Line of credit facility outstanding			$ 150,000,000	$ 120,000,000
Weighted average interest rate on debt			1.90%	2.20%
Available borrowings under senior secured revolving credit facility				$ 630,000,000
Line of credit facility, fair value of amount outstanding				119,100,000
Term Loan
2016 Notes:
Line of credit facility outstanding			$ 346,200,000	$ 342,500,000
Weighted average interest rate on debt			1.80%	2.10%
Long-term debt, fair value				$ 340,000,000
Convertible Debt
2016 Notes:
Deferred finance costs, gross			$ 500,000
Principal amount outstanding		$ 230,000,000	227,100,000	227,100,000
Interest rate on debt		1.625%
Portion of the debt proceeds that was classified as equity at the time of the offering		$ 43,200,000
Effective interest rate implicit in the liability component		5.60%
Carrying amount of liability			218,200,000	225,200,000
Unamortized discount			8,400,000	1,900,000
Fair value of outstanding borrowings				$ 356,000,000
Common stock based on initial conversion rate ratio		18.9287
Initial conversion price (in dollars per share) | $ / shares		$ 52.83
Maximum selling price of company's common stock		150.00%
Principal amount of notes per average trading price		$ 1,000
Maximum average conversion value of the Notes (less than or equal to)		98.00%
Number debt instruments pending conversion | convertible_debt_instrument					2,903
Repayments of debt			$ 2,900,000
Stock issued during period, conversion of convertible securities (in shares) | shares			8,457
Strike price of the call transaction (in dollars per share) | $ / shares		$ 52.83
Strike price of warrant transactions (in dollars per share) | $ / shares		$ 64.43
August 2015 Amendment
2016 Notes:
Senior credit facility, maximum borrowing capacity	$ 1,100,000,000
Cash balance threshold above which excess amount is not subject to any restriction of use or investment	$ 40,000,000
August 2015 Amendment | Minimum
2016 Notes:
Line of credit, commitment fee percentage	0.15%
August 2015 Amendment | Maximum
2016 Notes:
Line of credit, commitment fee percentage	0.30%
August 2015 Amendment | Revolving Credit Facility
2016 Notes:
Senior credit facility, maximum borrowing capacity	$ 750,000,000
August 2015 Amendment | Standby Letters of Credit
2016 Notes:
Senior credit facility, maximum borrowing capacity	60,000,000
August 2015 Amendment | Swingline Loan
2016 Notes:
Senior credit facility, maximum borrowing capacity	$ 60,000,000
August 2015 Amendment | Eurodollar
2016 Notes:
Interest rates available to the Company at its option	1.00%
August 2015 Amendment | Eurodollar | Minimum
2016 Notes:
Interest rates available to the Company at its option	1.00%
August 2015 Amendment | Eurodollar | Maximum
2016 Notes:
Interest rates available to the Company at its option	1.75%
August 2015 Amendment | Federal Funds
2016 Notes:
Interest rates available to the Company at its option	0.50%
August 2015 Amendment | Term Loan
2016 Notes:
Senior credit facility, maximum borrowing capacity	$ 350,000,000
August 2015 Amendment | Term Loan | Maximum
2016 Notes:
Proceeds from lines of credit	$ 200,000,000
July 2014 Amendment
2016 Notes:
Deferred finance costs, gross			$ 1,400,000