Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax [Line Items]
State income tax provision	$ 400,000	$ 900,000	$ 1,300,000
Foreign Income Tax Expense (Benefit)	200,000
Charitable contribution carryforwards	28,470,000	18,303,000
Federal R&D credit carryforwards	55,500,000
Increase in valuation allowance of deferred tax assets	9,800,000
Limitation on the utilization of NOLs, percentage				80.00%
Deferred tax asset , Switzerland tax reform	52,800,000	57,000,000.0
Unrecognized tax reserves recorded during period	2,900,000	1,900,000	3,100,000
Interest and/or penalties accrued	0	0
Interest and/or penalties	0	$ 0	$ 0
Federal
Income Tax [Line Items]
Operating loss carryforwards	539,200,000
Federal | Expiring in 2025
Income Tax [Line Items]
Operating loss carryforwards	6,900,000
Federal | Expiring in 2021
Income Tax [Line Items]
Charitable contribution carryforwards	120,800
State
Income Tax [Line Items]
Operating loss carryforwards	$ 416,300,000
Remaining net operating loss carryforward, expiration year	2026
Research and development credit carryforwards with no expiration date	$ 16,500,000
State | Expiring in 2024
Income Tax [Line Items]
Net operating loss carryforwards with no expiration date	2,600,000
State | Expiring in 2025 | Maximum
Income Tax [Line Items]
Operating loss carryforwards	100,000
State | Expiring in 2021
Income Tax [Line Items]
Charitable contribution carryforwards	120,800
Foreign
Income Tax [Line Items]
Operating loss carryforwards	$ 1,186,500,000
Remaining net operating loss carryforward, expiration year	2026
Net operating loss carryforwards with no expiration date	$ 3,700,000
Foreign | Operating Loss Carryforwards Expiring 2022
Income Tax [Line Items]
Operating loss carryforwards	1,186,500,000
Expire in 2021
Income Tax [Line Items]
Federal R&D credit carryforwards	$ 200,000