Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

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- Definition

The cash inflow from the issuance of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The cash outflow from the repayment of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder.

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CONVERTIBLE SENIOR NOTES - Additional Information (Details) - USD ($)	1 Months Ended		12 Months Ended
	Feb. 28, 2015	May 31, 2012	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2010	May 31, 2015	Dec. 31, 2012
Convertible Senior Notes:
Repayment of convertible senior notes			$ 0	$ 0	$ 857,541,000
Convertible Senior Notes 4.00 Percent Due 2015
Convertible Senior Notes:
Issued convertible senior notes, aggregate principal amount						$ 600,000,000
Issued convertible senior notes, interest rate						4.00%
Issued convertible senior notes, net proceeds following underwriting expenses						$ 582,000,000
Repurchase of convertible senior notes								$ 492,500,000
Repayment of convertible senior notes	$ 107,500,000
Convertible Senior Notes 5.00 Percent Due 2015
Convertible Senior Notes:
Issued convertible senior notes, aggregate principal amount		$ 750,000,000
Issued convertible senior notes, interest rate		5.00%
Issued convertible senior notes, net proceeds following underwriting expenses		$ 727,500,000
Debt instrument face amount							$ 750,000,000.0