CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
4.75% Convertible Senior Notes due 2015
Interest rate of debt (as a percent)	4.75%	4.75%	4.75%
1.25% Convertible Senior Notes due 2020
Interest rate of debt (as a percent)	1.25%	1.25%	1.25%

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

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(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

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Data Type:	num:percentItemType
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