Debt - Public Debt (Details) - 1.63% Convertible Notes, due 2019 - USD ($) $ in Millions	Oct. 15, 2019	Sep. 30, 2019
Debt Instrument [Line Items]
Long-term debt, interest rate (percentage)		1.63%
Subsequent Event
Debt Instrument [Line Items]
Long-term debt, interest rate (percentage)	1.63%
Debt, repurchase amount	$ 403

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant