Significant Accounting Policies - Narrative (Details) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended
	Mar. 20, 2019 USD ($)	Mar. 31, 2019 USD ($) $ / shares shares	Feb. 24, 2019 USD ($) region $ / shares shares	Feb. 25, 2018 USD ($)	Mar. 19, 2019 USD ($)	Feb. 12, 2019 vote class $ / shares shares	Feb. 11, 2019 $ / shares shares	Nov. 25, 2018 USD ($) $ / shares shares
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of geographical regions | region			3
Common stock, par value | $ / shares			$ 0.001			$ 0.001	$ 0.01	$ 0.001
Common stock, shares authorized | shares			2,700,000,000					2,700,000,000
Temporary equity			$ 322,984					$ 299,140
Accounting Standards Update 2017-07 [Member] | Other Income (Expense), Net [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest costs and investment earnings			$ 4,000	$ 800
IPO [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of classes of common stock | class						2
Common Class B [Member] | IPO [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Common stock, par value | $ / shares						$ 0.001
Number of votes per share of common stock | vote						10
Common Class A [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase amount (in shares) | shares							930,000,000
Common stock, shares authorized | shares						1,200,000,000
Common Class A [Member] | 2019 Equity Incentive Plan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of shares authorized under plan | shares						40,000,000
Common Class A [Member] | 2019 Employee Stock Purchase Plan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of shares authorized under plan | shares						12,000,000
Common Class A [Member] | IPO [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Common stock, par value | $ / shares						$ 0.001
Number of votes per share of common stock | vote						1
Subsequent Event [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Temporary equity					$ 350,000
Subsequent Event [Member] | Accrued Salaries, Wages and Employee Benefits [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock-based compensation expense	$ 50,000
Subsequent Event [Member] | Other Noncurrent Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock-based compensation expense	$ 9,000
Subsequent Event [Member] | Common Class A [Member] | IPO [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shares issued and sold (in shares) | shares		14,960,557
Shares issued and sold (usd per share) | $ / shares		$ 17.00
Net proceeds		$ 215,800
Underwriting discounts and commissions paid		38,500
Underwriting discounts and commissions paid on behalf of selling stockholders		24,900
Offering expenses		$ 7,000