Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: 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

Name:	us-gaap_SecuredLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Long-Term Debt (Details 1) (USD $)	Sep. 30, 2014 2.25% Convertible Senior Notes due 2036 [Member]	Sep. 02, 2014 2.25% Convertible Senior Notes due 2036 [Member]	Dec. 31, 2013 2.25% Convertible Senior Notes due 2036 [Member]	Sep. 30, 2014 3.00% Convertible Senior Notes due 2020 [Member]	Jun. 25, 2014 3.00% Convertible Senior Notes due 2020 [Member]	Dec. 31, 2013 3.00% Convertible Senior Notes due 2020 [Member]
Carrying value of Notes related discount and equity component
Debt Instrument, Face Amount	$ 182,800,000	$ 182,500,000			$ 115,000,000
Secured Long-term Debt, Noncurrent	$ 0		$ 160,334,000	$ 0		$ 84,305,000