Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended	9 Months Ended		12 Months Ended
	Jul. 13, 2016	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Business And Significant Accounting Policies [Line Items]
Intangible asset impairment			$ 28.0
Merger consideration compensation expense				$ 164.1
Reclassification of other current assets to debt					$ 9.2
Decrease in long-term debt					58.9
Reclassification of other assets to debt					$ 49.7
Restricted stock withholdings			5.3	$ 10.5
Recognized excess tax benefit from provision for income taxes		$ 5.6	12.5
LDR Holding Corporation [Member]
Business And Significant Accounting Policies [Line Items]
Merger consideration compensation expense	$ 24.1	24.1	24.1
Employee Severance [Member]
Business And Significant Accounting Policies [Line Items]
Restructuring Cost		170.0	170.0
Cumulative restructuring cost		115.3	115.3
Contract Terminations [Member]
Business And Significant Accounting Policies [Line Items]
Restructuring Cost		130.0	130.0
Cumulative restructuring cost		123.8	123.8
In Process Research and Development (IPR&D) [Member]
Business And Significant Accounting Policies [Line Items]
Intangible assets recognized as part of merger		$ 209.0	209.0
Intangible asset impairment			$ 28.0