Commitments and Contingencies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) complaint	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Other Commitments [Line Items]
Other assets from government payors related to disputed findings	$ 16,900
Additional complaints filed | complaint	2
Purchase amount of property	$ 32,993	$ 10,176	$ 16,009
Amount required for expansion plan	70,000
Early phase commitment	$ 4,000
Joint venture buy/sell option period	30 days
Lafayette
Other Commitments [Line Items]
Purchase amount of property	$ 19,300