CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (Parenthetical)	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
1 Percent Convertible Senior Notes [Member]
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Interest rate on convertible senior notes	1.00%	1.00%	1.00%
2 3/4 Percent Convertible Senior Notes [Member]
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Interest rate on convertible senior notes	2.75%	2.75%	2.75%

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

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant