Business Combinations - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended	6 Months Ended
	Oct. 27, 2016	Apr. 19, 2016	Mar. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill				$ 1,929,283	$ 1,924,052
Contribution and investment agreement date				Mar. 20, 2016
Homecare Business [Member]
Business Acquisition [Line Items]
Escrow deposit related to the integration of homecare business		$ 15,000		$ 12,800
Escrow deposit period		5 years
Netsmart [Member]
Business Acquisition [Line Items]
Netsmart transaction completion date				Apr. 19, 2016
HealthMEDX, LLC [Member]
Business Acquisition [Line Items]
Date of acquisition	Oct. 27, 2016
Business combination, aggregate consideration	$ 39,200
Business combination, adjustment of fair value of liability			$ 100
Increase in goodwill from subsequent adjustment of liability			$ 100
Asset Purchase Agreement [Member]
Business Acquisition [Line Items]
Asset purchase agreement date			Mar. 31, 2017
Aggregate cash consideration to acquire intellectual property, certain contractual relationships and certain associates			$ 4,000
Business combination, estimated consideration payable			700
Contingent consideration, fair value				$ 500
Goodwill			$ 4,400