Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Cumulative unremitted earnings of overseas subsidiaries	$ 369,000
Less: valuation allowance	(253,649)	$ (242,059)	$ (219,093)	$ (172,797)
Federal research and development credits	48,600
State tax credits	$ 23,000
Minimum
Income Taxes [Line Items]
Period after loss carryforwards utilized that tax returns remain open to examination	3 years
Maximum
Income Taxes [Line Items]
Period after loss carryforwards utilized that tax returns remain open to examination	4 years
U.S. state
Income Taxes [Line Items]
Less: valuation allowance	$ (20,900)
Operating loss carryforwards	43,200
U.S. state | Rodin Therapeutics, Inc.
Income Taxes [Line Items]
Operating loss carryforwards	43,200
Federal research and development credits	400
U.S. federal
Income Taxes [Line Items]
Operating loss carryforwards	33,300
U.S. federal | Rodin Therapeutics, Inc.
Income Taxes [Line Items]
Operating loss carryforwards	51,300
Federal research and development credits	700
Ireland
Income Taxes [Line Items]
Income taxes payable on repatriation of unremitted earnings	38,000
Less: valuation allowance	(232,800)
Operating loss carryforwards	$ 1,600,000