Restructuring - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended	21 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ (467,000)	$ 11,984,000	$ 27,791,000	$ 23,542,000
Quest [Member]
Restructuring Cost and Reserve [Line Items]
Severance, facility closure and other exit-related costs					$ 14,000,000
2016 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring plan approved	$ 41,000,000		41,000,000			$ 41,000,000
2016 Plan [Member] | Operating Segments [Member] | Product Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs			22,300,000
2016 Plan [Member] | Operating Segments [Member] | Integrated Healthcare Services [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs			2,200,000
2016 Plan [Member] | Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs			$ 2,100,000
2015 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring plan approved					$ 30,000,000
2015 Plan [Member] | Operating Segments [Member] | Product Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs						12,000,000
2015 Plan [Member] | Operating Segments [Member] | Product Development [Member] | Quest [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs						9,600,000
2015 Plan [Member] | Operating Segments [Member] | Integrated Healthcare Services [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs						8,900,000
2015 Plan [Member] | Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs						$ 952,000