Company-wide Realignments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Restructuring Cost And Reserve [Line Items]
Restructuring charges		$ 0.2
Reversal of non-cash-stock-based compensation expense		0.4	$ 0.9
Restructuring costs		5.8	$ 5.8
One time termination benefits		4.1
Payments for restructuring		2.6
Tetraphase Pharmaceuticals, Inc.
Restructuring Cost And Reserve [Line Items]
Restructuring costs	$ 3.1	3.1
Payments for restructuring		1.3
Accrued Payroll and Related Expenses
Restructuring Cost And Reserve [Line Items]
Restructuring charges		1.5
Payments for restructuring		4.9
Accrued Payroll and Related Expenses | Tetraphase Pharmaceuticals, Inc.
Restructuring Cost And Reserve [Line Items]
Restructuring charges		$ 1.8