Intangible Assets, Net - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 171,113,000	$ 6,900,000
Estimated intangible assets useful life	19 years
Impairment of intangible assets, finite-lived	$ 0	$ 0
Paragon Medical
Finite-Lived Intangible Assets [Line Items]
Intangible assets	163,500,000		$ 164,200,000
Other
Finite-Lived Intangible Assets [Line Items]
Intangible assets	5,700,000
Southern California Technical Arts, Inc.
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 1,900,000