Commitments and Contingencies - Additional Information (Detail)	Jul. 26, 2019 USD ($)
Commitment And Contingencies [Line Items]
Purchase amended and restated agreement date	Oct. 01, 2017
Purchase amended and restated agreement effective date	Jan. 01, 2017
TCS
Commitment And Contingencies [Line Items]
Purchase amended and restated agreement date	Jul. 01, 2019
Purchase amended and restated agreement effective date	Jan. 01, 2019
Commitment
Commitment And Contingencies [Line Items]
Purchase commitment, remaining minimum amount committed	$ 1,413,000,000
Services 2019 | Minimum
Commitment And Contingencies [Line Items]
Commitment to purchase services	275,000,000
Services 2020 | Minimum
Commitment And Contingencies [Line Items]
Commitment to purchase services	250,000,000
Services Per Year From 2021 Through 2024
Commitment And Contingencies [Line Items]
Commitment to purchase services	184,300,000
Services 2025
Commitment And Contingencies [Line Items]
Commitment to purchase services	$ 137,800,000