Convertible Senior Notes - Equity Components (Details) $ in Thousands	Jun. 30, 2017 USD ($)
2022 Notes
Debt Instrument [Line Items]
Note	$ 162,039
Issuance cost	(2,148)
Net amount recorded in equity	159,891
2018 Notes
Debt Instrument [Line Items]
Note	155,319
Issuance cost	(3,257)
Net amount recorded in equity	$ 152,062

The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031897-161870

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