Debt (Tables)

9 Months Ended

Sep. 30, 2018

Debt Disclosure [Abstract]

Convertible Debenture Terms

The following table summarizes at September 30, 2018 the related balances, conversion rate and conversion price of the Debentures:

Outstanding principal amount	$	361
Unamortized debt discount	$	118
Net debt carrying amount	$	239
Equity component carrying amount	$	131
Conversion rate (shares of common stock per $1,000 of principal amount)	13.8258
Effective conversion price (per $1,000 of principal amount)	$	72.3280