Calculations of Earnings (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic earnings (loss) per Common Share:
Loss from continuing operations, net of tax	$ (7,977)	$ (25,161)
Net loss attributable to non-controlling interests	424	790
Net loss from continuing operations attributable to Allscripts Healthcare Solutions, Inc. stockholders	(7,553)	(24,371)
Loss from discontinued operations, net of tax	0	(3,354)
Accretion of redemption preference on redeemable convertible non-controlling interest - discontinued operations	0	(12,149)
Net loss from discontinued operations attributable to Allscripts Healthcare Solutions, Inc. stockholders	0	(15,503)
Net loss attributable to Allscripts Healthcare Solutions, Inc. stockholders	$ (7,553)	$ (39,874)
Weighted-average common shares outstanding	169,957	179,882
Basic earnings (loss) from continuing operations per Common Share	$ (0.04)	$ (0.14)
Basic income from discontinued operations per Common Share	0.00	(0.08)
Net loss attributable to Allscripts Healthcare Solutions, Inc. stockholders per share	$ (0.04)	$ (0.22)
Diluted earnings (loss) per Common Share:
Loss from continuing operations, net of tax	$ (7,977)	$ (25,161)
Net loss attributable to non-controlling interests	424	790
Net loss from continuing operations attributable to Allscripts Healthcare Solutions, Inc. stockholders	(7,553)	(24,371)
Loss from discontinued operations, net of tax	0	(3,354)
Accretion of redemption preference on redeemable convertible non-controlling interest - discontinued operations	0	(12,149)
Net loss from discontinued operations attributable to Allscripts Healthcare Solutions, Inc. stockholders	0	(15,503)
Net loss attributable to Allscripts Healthcare Solutions, Inc. stockholders	$ (7,553)	$ (39,874)
Weighted-average common shares outstanding	169,957	179,882
Plus: Dilutive effect of stock options, restricted stock unit awards and warrants	0	0
Weighted-average common shares outstanding assuming dilution	169,957	179,882
Diluted earnings (loss) from continuing operations per Common Share	$ (0.04)	$ (0.14)
Diluted income from discontinued operations per Common Share	0.00	(0.08)
Net loss attributable to Allscripts Healthcare Solutions, Inc. stockholders per share	$ (0.04)	$ (0.22)