Income Taxes - Narrative (Details) - USD ($)
|
3 Months Ended |
12 Months Ended |
|
|
Dec. 31, 2018 |
Dec. 31, 2019 |
Dec. 31, 2017 |
Dec. 31, 2016 |
| Tax Carryforwards [Line Items] |
|
|
|
|
| Decrease in valuation allowance |
|
$ 30,500,000
|
|
|
| Income tax (benefit) resulting in the release of valuation allowance |
$ (1,560,000,000)
|
|
|
|
| Valuation allowance |
168,491,000
|
205,192,000
|
|
|
| Unrecognized tax benefits |
$ 19,549,000
|
33,920,000
|
$ 3,814,000
|
$ 0
|
| Income tax penalties and interest accrued |
|
0
|
|
|
| Domestic and Foreign Tax Authority |
|
|
|
|
| Tax Carryforwards [Line Items] |
|
|
|
|
| Valuation allowance |
|
205,200,000
|
|
|
| Domestic Tax Authority |
|
|
|
|
| Tax Carryforwards [Line Items] |
|
|
|
|
| Operating loss carryforwards |
|
1,500,000,000
|
|
|
| Operating loss carryforwards, subject to expiration |
|
1,300,000,000
|
|
|
| Operating loss carryforwards, not subject to expiration |
|
181,100,000
|
|
|
| Tax credit carryforwards |
|
399,000,000.0
|
|
|
| State and Local Jurisdiction |
|
|
|
|
| Tax Carryforwards [Line Items] |
|
|
|
|
| Operating loss carryforwards |
|
903,700,000
|
|
|
| Tax credit carryforwards |
|
161,700,000
|
|
|
| Foreign Tax Authority |
|
|
|
|
| Tax Carryforwards [Line Items] |
|
|
|
|
| Operating loss carryforwards |
|
896,900,000
|
|
|
| Operating loss carryforwards, subject to expiration |
|
16,000,000.0
|
|
|
| Operating loss carryforwards, not subject to expiration |
|
880,900,000
|
|
|
| Deferred Tax Assets |
|
|
|
|
| Tax Carryforwards [Line Items] |
|
|
|
|
| Unrecognized tax benefits |
|
13,400,000
|
|
|
| Accounts Payable and Accrued Liabilities |
|
|
|
|
| Tax Carryforwards [Line Items] |
|
|
|
|
| Unrecognized tax benefits |
|
20,500,000
|
|
|
| Semma Therapeutics, Inc. |
|
|
|
|
| Tax Carryforwards [Line Items] |
|
|
|
|
| Business combination, recognized identifiable assets acquired and liabilities assumed, deferred tax liabilities, current |
|
$ 54,200,000
|
|
|