LONG-TERM DEBT / INTEREST EXPENSE (Details) - USD ($)		3 Months Ended		12 Months Ended
	Apr. 10, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Debt Instrument
Borrowings outstanding		$ 1,515,382,000		$ 1,540,453,000
Additional borrowings outstanding from the revolving credit facility		64,000,000	$ 90,000,000
Subsequent Event
Debt Instrument
Excess cash flow payment	$ 39,700,000
Payments for excess cash flows, paid with cash on hand	11,500,000
Revolving Credit Facility
Debt Instrument
Maximum borrowing capacity		$ 300,000,000
Weighted average interest rate		3.10%		2.70%
Commitment fee on undrawn portion of revolving credit facility		0.50%		0.50%
Line of credit facility, remaining borrowing capacity		$ 194,300,000
Revolving Credit Facility | Subsequent Event
Debt Instrument
Additional borrowings outstanding from the revolving credit facility	$ 28,200,000
Letter Of Credit
Debt Instrument
Outstanding letters of credit fee		2.50%		2.50%
Letters of credit outstanding		$ 5,700,000
Term Loan Facility
Debt Instrument
Maximum borrowing capacity		$ 1,200,000,000
Effective interest rate		3.49%		3.27%
Borrowings outstanding		$ 1,169,520,000		$ 1,170,486,000
Credit Facility | Revolving Credit Facility
Debt Instrument
Borrowings outstanding		100,000,000		127,000,000
Convertible Senior Notes | 1.5% Convertible Senior Notes, Due 2020
Debt Instrument
Borrowings outstanding		247,924,000		245,273,000
Principal		$ 287,500,000		$ 287,500,000
Interest rate		1.50%