Business Combinations and Other Investments - Other Acquisitions and Investments - Additional Information (Detail) - USD ($)					3 Months Ended	12 Months Ended
	Dec. 02, 2016	Oct. 14, 2016	Sep. 08, 2016	Apr. 17, 2015	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 21, 2017	Apr. 19, 2016
Business Acquisition [Line Items]
Equity ownership percentage	100.00%	100.00%								49.10%
Goodwill					$ 1,924,052,000	$ 2,004,953,000	$ 1,924,052,000	$ 1,222,601,000
Date of acquisition		Oct. 14, 2016
Total consideration for non marketable equity securities						5,606,000	21,185,000	$ 215,786,000
Carrying values of cost method investments					26,041,000		26,041,000		$ 26,755,000
Equity Method Debt Investments [Member]
Business Acquisition [Line Items]
Total consideration for non-marketable convertible note of a third party						2,600,000
Cost Method Debt Investments [Member]
Business Acquisition [Line Items]
Total consideration for non-marketable convertible note of a third party							1,000,000
Other Assets [Member] | Equity Method Debt Investments [Member]
Business Acquisition [Line Items]
Convertible note carrying value						2,600,000
Other Assets [Member] | Cost Method Debt Investments [Member]
Business Acquisition [Line Items]
Convertible note carrying value					1,000,000	$ 1,000,000	1,000,000
Third Party
Business Acquisition [Line Items]
Equity ownership percentage			51.00%
Majority interest acquired in a third party	$ 5,100,000	$ 24,000,000	$ 29,700,000	$ 11,100,000
Goodwill	2,900,000	16,200,000	46,200,000	22,300,000
Intangible assets				4,300,000
Liabilities assumed, deferred tax liabilities net	1,200,000	3,700,000	8,500,000
Estimated fair value of the aggregate consideration of net working capital and deferred revenue	600,000	200,000
Business combination, estimated consideration payable	2,500,000
Contingent consideration, fair value					2,000,000		2,000,000
Accounts receivable, net			5,900,000
Assets Acquired, deferred tax assets			600,000
Assets acquired, fixed assets			1,500,000
Liabilities assumed, accounts payable, deferred revenue and accruals			6,000,000
Other long-term liabilities			800,000
Estimated fair value of non controlling interest			$ 29,400,000	11,000,000
Decrease in deferred tax liability					(200,000)
Increase in the residual allocation to goodwill					1,000,000
Minority interest percentage			49.00%
Description of call feature						the minority owners of the third party were granted a call option to repurchase the 51% equity share owned by Allscripts at the same pre-defined future enterprise value applicable to Allscripts call option for a period of 9 months after the third anniversary of the transaction date. Such call option can only be exercised in the event that Allscripts chooses not to exercise its call option after the third anniversary of the transaction date.
Provided loan to third party to refinance outstanding indebtedness				$ 9,300,000
Third Party | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets	$ 3,400,000	200,000	$ 8,300,000
Intangible assets, useful life (in years)	8 years		13 years			8 years
Decrease in the value of customer relationship intangibles					(1,200,000)
Third Party | Technology [Member]
Business Acquisition [Line Items]
Intangible assets	$ 600,000	$ 11,500,000	$ 10,300,000
Intangible assets, useful life (in years)	8 years		10 years			8 years
Third Party | Tradenames [Member]
Business Acquisition [Line Items]
Intangible assets			$ 1,600,000
Intangible assets, useful life (in years)			10 years
2017 Business Acquisitions [Member] | Cost Method Equity Investments
Business Acquisition [Line Items]
Total consideration for non marketable equity securities						$ 2,800,000
2017 Business Acquisitions [Member] | Other Assets [Member] | Cost Method Equity Investments
Business Acquisition [Line Items]
Carrying values of cost method investments						2,800,000
2016 Business Acquisitions [Member] | Cost Method Equity Investments
Business Acquisition [Line Items]
Total consideration for non marketable equity securities							10,200,000
2016 Business Acquisitions [Member] | Other Assets [Member] | Cost Method Equity Investments
Business Acquisition [Line Items]
Carrying values of cost method investments					$ 10,200,000	$ 10,200,000	$ 10,200,000