Equity Incentive Plans (Tables)

9 Months Ended

Sep. 30, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Operational Milestone Based on Revenue or Adjusted EBITDA

Total Revenue (in billions)	Adjusted EBITDA (in billions)
$20.0	$1.5
$35.0	$3.0
$55.0	$4.5
$75.0	$6.0
$100.0	$8.0
$125.0	$10.0
$150.0	$12.0
$ 175.0	$14.0

Summary of Stock-Based Compensation Expense

The following table summarizes our stock-based compensation expense by line item in the consolidated statements of operations (in thousands):

	Three Months Ended  September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Cost of sales	$	25,037	$	10,166	$	59,203	$	27,663
Research and development		65,718		51,066		192,762		158,052
Selling, general and administrative		113,973		51,421		287,869		146,697
Restructuring and other		—		—		3,877		—
Total	$	204,728	$	112,653	$	543,711	$	332,412