Quarterly report pursuant to Section 13 or 15(d)

Debt and Secured Revolving Line of Credit (Convertible Debt) (Details)

v3.10.0.1
Debt and Secured Revolving Line of Credit (Convertible Debt) (Details) - 2.125% Convertible Senior Notes due 2026 - USD ($)
Jun. 30, 2018
Dec. 30, 2017
Sep. 30, 2016
Debt Instrument [Line Items]      
Principal $ 805,000,000 $ 805,000,000 $ 805,000,000
Unamortized debt discount (274,000,000) (286,000,000)  
Unamortized debt issuance costs (11,000,000) (12,000,000)  
Net carrying amount 520,000,000 507,000,000  
Carrying amount of the equity component, net 305,000,000 $ 305,000,000  
Equity issuance costs $ 9,000,000