Summary of Significant Accounting Policies - Schedule of Net Revenue by Service Line (Detail) - Product Concentration Risk [Member] - Sales Revenue, Services, Net [Member]	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Net revenue in percentage	100.00%	100.00%	100.00%
Neonatology and Other Pediatric Subspecialties [Member]
Segment Reporting Information [Line Items]
Net revenue in percentage	80.00%	79.00%	77.00%
Maternal-Fetal Medicine [Member]
Segment Reporting Information [Line Items]
Net revenue in percentage	16.00%	16.00%	18.00%
Pediatric Cardiology [Member]
Segment Reporting Information [Line Items]
Net revenue in percentage	4.00%	5.00%	5.00%