Revenue Recognition - Schedule of Revenues Disaggregated by Service Line (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Disaggregation Of Revenue [Line Items]
Total services	$ 207,233,000	$ 202,303,000	$ 195,522,000	$ 190,253,000	$ 185,443,000	$ 179,386,000	$ 177,426,000	$ 176,307,000	$ 795,311,000	$ 718,562,000	$ 646,230,000
Patient Management Services [Member]
Disaggregation Of Revenue [Line Items]
Total services									529,995,000	478,751,000	424,050,000
Network Solutions Services [Member]
Disaggregation Of Revenue [Line Items]
Total services									$ 265,316,000	$ 239,811,000	$ 222,180,000