Acquisitions (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended				6 Months Ended		12 Months Ended
	Oct. 31, 2020	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Cash paid, net of cash acquired						$ 35,349	$ 16,788
Additional consideration	$ 3,600
Acquisition-related costs		$ 200				400
General and Administrative Expense [Member]
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Acquisition-related costs		400				800
2020 Acquisition activity, O&P business
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Cash paid, net of cash acquired				$ 4,900	$ 16,800			$ 21,709
Issuance of Seller Notes at fair value				1,900	21,900			23,766
Deferred payment obligations at fair value					3,500			3,468
Additional consideration				300	4,000			4,319
Aggregate purchase price				7,100	46,200			53,262
Accounts receivable				4,224				4,224
Inventories				2,276				2,276
Other assets and liabilities, net				(4,561)				(4,561)
Net assets acquired				8,497				8,497
Goodwill								44,765
Operating right-of-use assets				5,500				5,500
Operating lease liabilities				5,500				5,500
Consideration through settlement of amounts due from acquiree					400
2020 Acquisition activity, O&P business | Noncompete Agreements [Member]
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Other intangible assets, net				200				$ 200
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life								5 years
2020 Acquisition activity, O&P business | Customer Relationships [Member]
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Other intangible assets, net				$ 6,358				$ 6,358
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life								5 years
2020 Acquisition activity, O&P business | Payable in lump sum payment due in October 2020
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Issuance of Seller Notes at fair value					18,100
2020 Acquisition activity, O&P business | Payable in annual installments over a period of 3 years
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Issuance of Seller Notes at fair value					$ 3,800
Beginning period for the deferred payment obligations payable					4 years
Thereafter period for payable deferred payment obligations					3 years
2021 Acquisition activity, two O&P business
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Cash paid, net of cash acquired		16,000
Issuance of Seller Notes at fair value		4,900
Additional consideration		100
Aggregate purchase price		21,000
2021 Acquisition activity, three O&P business
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Cash paid, net of cash acquired			$ 19,200			35,199
Issuance of Seller Notes at fair value			4,000			8,893
Additional consideration			1,000			1,101
Aggregate purchase price			$ 24,200			45,193
Accounts receivable		2,114				2,114
Inventories		1,631				1,631
Other assets and liabilities, net		(3,720)				(3,720)
Net assets acquired		4,520				4,520
Goodwill						40,673
Operating right-of-use assets		2,600				2,600
Operating lease liabilities		2,600				2,600
2021 Acquisition activity, three O&P business | Customer Relationships [Member]
Aggregate purchase price of this acquisition was allocated on a preliminary basis
Other intangible assets, net		$ 4,495				$ 4,495
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life						5 years