Fair Value of Financial Assets and Liabilities - Summary of Fair Value and Carrying Value of Long-Term Debt (Detail) - USD ($) $ in Thousands		Jun. 30, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total debt		$ 824,239	$ 1,188,661
Term Loan Facility [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Term Loans	[1]	725,000
Term loans	[2]	721,451
2024 Senior Secured Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Long Term Debt	[1]		1,045,000
Total debt	[3]		973,539
2022 Convertible Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Convertible Notes	[1]	194,000	404,000
Carrying Value of Convertible Notes		$ 102,788	$ 215,122	[4]

[1] Fair value amounts are rounded to the nearest million.

[2] Carrying value of the Term Loan Facility reflects the unaccreted debt discount of $3.5 million as of June 30, 2021. See Note 10, “Long-Term Debt and Other Liabilities,” for further information.

[3] Carrying value of the 2024 Senior Secured Notes reflects the unaccreted debt discount of $1.5 million as of December 31, 2020. See Note 10, “Long-Term Debt and Other Liabilities,” for further information.

[4] Carrying value of the 2022 Convertible Notes reflects the unaccreted debt discount of $22.6 million as of December 31, 2020. See Note 10, “Long-Term Debt and Other Liabilities,” for further information.