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Net Loss Per Share - Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - $ / shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	May 15, 2020
September 1, 2026 \| Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			11,492
Conversion Price per Share (usd per share)	$ 43.51		$ 43.51
May 15, 2025 \| Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			8,408
Conversion Price per Share (usd per share)	67.20		$ 67.20		$ 67.20
September 1, 2024 \| Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			15,468
Conversion Price per Share (usd per share)	43.51		$ 43.51
July 1, 2023 \| Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			4,769
Conversion Price per Share (usd per share)	78.37		$ 78.37
December 1, 2021 \| Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion Spread (in shares)			5,067
Conversion Price per Share (usd per share)	$ 52.36		$ 52.36
Class A Common Stock and Class C Capital Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	41,920	27,143	38,719	26,615
Class A Common Stock and Class C Capital Stock \| Weighted average \| Option Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	25,202	19,502	22,649	19,656
Class A Common Stock and Class C Capital Stock \| Weighted average \| Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	9,086	7,230	8,354	6,548
Class A Common Stock \| December 15, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	400	411	400	411
Class C Capital Stock \| December 15, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total Class A common stock and Class C capital stock equivalents (in shares)	7,232	0	7,316	0