Commitments and Contingencies - Narrative (Details)	1 Months Ended			3 Months Ended	12 Months Ended
	Apr. 30, 2023 USD ($) service	Feb. 28, 2021 USD ($) ft²	Mar. 31, 2020 USD ($) ft²	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets					$ 19,657,000	$ 24,707,000
Lease liabilities					28,272,000	31,091,000
Lease payments					5,600,000	5,700,000
Impairment of operating lease right of use asset and leasehold improvements					2,915,000	0
Impairment of long-lived assets, right-of-use asset					2,300,000
Impairment of long-lived assets, related leasehold improvements				$ 600,000	600,000
Impairment of operating lease right of use asset and leasehold improvements						0
Prepaid expenses and other current assets					5,781,000	6,106,000
Tempus Labs, Inc.
Lessee, Lease, Description [Line Items]
Payments for purchase obligation					3,600,000	1,100,000	$ 0
Prepaid expenses and other current assets					700,000	800,000
Purchase Obligation, Quarterly Payment Terms	30 days
Tempus Labs, Inc. | Research And Development Services
Lessee, Lease, Description [Line Items]
Services contract term	4 years
Number of primary services | service	3
Annual minimum commitment payment in year one	$ 1,500,000
Annual minimum commitment payment in year two	2,500,000
Annual minimum commitment payment in year three	3,000,000
Annual minimum commitment payment in year four	2,500,000
Sales milestone payment	$ 22,400,000
Sales milestone payment in shares of common stock, percent threshold	50.00%
Research and development expenses
Lessee, Lease, Description [Line Items]
Impairment of operating lease right of use asset and leasehold improvements					1,900,000
General and administrative expenses
Lessee, Lease, Description [Line Items]
Impairment of operating lease right of use asset and leasehold improvements					1,000,000
301 Binney Street, Cambridge, Massachusetts
Lessee, Lease, Description [Line Items]
Lease term			11 years
Facility size | ft²			40,514
Annual base rent			$ 4,100,000
Escalating rent payments, percent			3.00%
Letter of credit			$ 2,000,000
Tenant improvement allowances			$ 3,700,000
Operating lease right-of-use assets					17,900,000	21,900,000
Lease liabilities					$ 25,600,000	28,000,000
Remaining lease term					7 years 2 months 12 days
Incremental borrowing rate					8.50%
San Mateo, California. February 2021 Lease Agreement
Lessee, Lease, Description [Line Items]
Facility size | ft²		17,340
Escalating rent payments, percent		3.00%
Operating lease right-of-use assets					$ 1,700,000	2,800,000
Lease liabilities					$ 2,700,000	$ 3,700,000
Remaining lease term					2 years 6 months
Incremental borrowing rate					11.18%
Initial annual base rent		$ 1,200,000
Security deposit		$ 59,000