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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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

Commitments and Contingencies - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2017	Dec. 31, 2016	Nov. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Legal settlements	$ 270,000,000.0
2022 convertible senior notes
Debt Instrument [Line Items]
Face amount of debt		$ 782,500,000	$ 0
2018 convertible senior notes
Debt Instrument [Line Items]
Face amount of debt		$ 575,000,000	$ 575,000,000	$ 575,000,000.0