Summary of Significant Accounting Policies - Components of Property, Building and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property, building and equipment, gross	$ 268,710	$ 252,353
Less accumulated depreciation	114,427	98,394
Property, building and equipment, net	154,283	153,959
Land
Property, Plant and Equipment [Line Items]
Property, building and equipment, gross	7,339	7,339
Building and leasehold improvements
Property, Plant and Equipment [Line Items]
Property, building and equipment, gross	111,858	105,444
Transportation equipment
Property, Plant and Equipment [Line Items]
Property, building and equipment, gross	20,442	19,898
Office furniture and medical equipment
Property, Plant and Equipment [Line Items]
Property, building and equipment, gross	129,071	117,084
Construction in progress
Property, Plant and Equipment [Line Items]
Property, building and equipment, gross	$ 0	$ 2,588