Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	Jul. 01, 2021	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		$ 157,936	$ 172,905
Fair value noncontrolling interest in HCS Venture		103,808	4,898
Total long-term debt		3,857,459	3,915,988
Securities Purchase Agreement | HCA Healthcare, Inc. | Health Care Services
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value noncontrolling interest in HCS Venture	$ 100,000
Sale of stock, percentage of ownership after transaction	20.00%
Sale of stock, consideration received on transaction	$ 400,000
Long-term debt and lines of credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long-term debt		3,900,000	$ 3,900,000
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		$ 157,900