The Company, Business Activities and Basis of Presentation - Summary of Third-Party Payers That Represent More Than 10% of Total Net Revenues and Total Net Accounts Receivable and Their Related Percentage (Detail)	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Customer Concentration Risk [Member] | Net Revenues [Member] | Medicare and Medicare Advantage [Member] | Cares Act [Member]
Concentration Risk [Line Items]
Concentration risk percentage	43.00%	35.00%
Customer Concentration Risk [Member] | Net Revenues [Member] | Blue Cross Blue Shield [Member]
Concentration Risk [Line Items]
Concentration risk percentage	16.00%	30.00%
Customer Concentration Risk [Member] | Net Revenues [Member] | Kaiser Permanente [Member]
Concentration Risk [Line Items]
Concentration risk percentage	14.00%	3.00%
Credit Concentration Risk [Member] | Net Accounts Receivable [Member] | Medicare and Medicare Advantage [Member] | Cares Act [Member]
Concentration Risk [Line Items]
Concentration risk percentage	36.00%		31.00%
Credit Concentration Risk [Member] | Net Accounts Receivable [Member] | Blue Cross Blue Shield [Member]
Concentration Risk [Line Items]
Concentration risk percentage	16.00%		19.00%