Acquisitions - Summary of Fair Values of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Jan. 31, 2019	Apr. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill			$ 71,177	$ 72,401
Spinal Kinetics [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		$ 6,785
Restricted cash		30
Accounts receivable		1,705
Inventories		8,175
Prepaid expenses and other current assets		315
Property, plant and equipment		2,285
Other long-term assets		320
Deferred income taxes		3,594
Total identifiable assets acquired		62,509
Accounts payable		351
Other current liabilities		2,869
Other long-term liabilities		301
Total liabilities assumed		3,521
Goodwill		17,612
Total fair value of consideration transferred		76,600
Options Medical [Member]
Business Acquisition [Line Items]
Total identifiable assets acquired	$ 6,575
Total liabilities assumed	175
Total fair value of consideration transferred	6,400
Options Medical [Member] | Operating Lease Liability - Short-term [Member]
Business Acquisition [Line Items]
Other current liabilities	69
Options Medical [Member] | Operating Lease Liability - Long-term [Member]
Business Acquisition [Line Items]
Other long-term liabilities	106
Options Medical [Member] | Operating Lease Assets [Member]
Business Acquisition [Line Items]
Other long-term assets	175
Developed Technology [Member] | Spinal Kinetics [Member]
Business Acquisition [Line Items]
Finite lived intangible assets, net acquired		$ 12,400
Assigned Useful Life		10 years
In-process Research and Development ("IPR&D") [Member] | Spinal Kinetics [Member]
Business Acquisition [Line Items]
Finite lived intangible assets, net acquired		$ 26,800
Assigned Useful Life		10 years
Tradename [Member] | Spinal Kinetics [Member]
Business Acquisition [Line Items]
Finite lived intangible assets, net acquired		$ 100
Assigned Useful Life		2 years
Customer Relationships [Member] | Options Medical [Member]
Business Acquisition [Line Items]
Finite lived intangible assets, net acquired	$ 5,832
Assigned Useful Life	10 years
Assembled Workforce [Member] | Options Medical [Member]
Business Acquisition [Line Items]
Finite lived intangible assets, net acquired	$ 568
Assigned Useful Life	5 years