FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS (Tables)

3 Months Ended

Mar. 31, 2016

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The carrying amounts and fair values of the Company’s financial instruments at March 31, 2016 and December 31, 2015 are indicated below (in thousands): 

	As of March 31, 2016
					Fair Value Measurement Based on
	Carrying Amount		Fair Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Deferred Compensation Plan assets(1)	$	30,733	$	30,733	$	—	$	30,733	$	—
Liabilities
2% Convertible senior notes due June 2022(2)	$	600,000	$	536,472	$	536,472	$	—	$	—
Deferred Compensation Plan liabilities(1)	$	27,766	$	27,766	$	—	$	27,766	$	—

	As of December 31, 2015
					Fair Value Measurement Based on
	Carrying Amount		Fair Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Deferred Compensation Plan assets(1)	$	30,726	$	30,726	$	—	$	30,726	$	—
Liabilities
2% Convertible senior notes due June 2022(2)	$	600,000	$	602,250	$	602,250	$	—	$	—
Deferred Compensation Plan liabilities(1)	$	25,581	$	25,581	$	—	$	25,581	$	—

(1) The Deferred Compensation Plan liabilities are non-current liabilities recorded at the value of the amount owed to the plan participants, with changes in value recognized as compensation expense in the Company’s consolidated statements of operations. The calculation of the Deferred Compensation Plan obligation is derived from observable market data by reference to hypothetical investments selected by the participants and is included in the line items captioned “Other non-current liabilities” on the Company’s consolidated balance sheets. The Company invests participant contributions in corporate-owned life insurance (“COLI”) policies, for which the cash surrender value is included in the line item captioned “Other non-current assets” on the Company’s consolidated balance sheets.

(2) The difference between the amount shown as the carrying value in the above tables and the amount shown on the Company’s consolidated balance sheets at March 31, 2016 and December 31, 2015 represents the unaccreted discounts related to deferred debt issuance costs and bifurcation of the conversion feature of the notes.