Selected Segment Financial Data, Revenues and Operating Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Revenues	$ 234,995	$ 240,599	$ 444,305	$ 472,061
Stock-based compensation	(7,705)	(8,343)	(14,067)	(14,640)
Corporate and unallocated expenses	(21,498)	(66,500)	(41,512)	(92,330)
Interest, net	(6,975)	(10,514)	(13,596)	(20,568)
Other, net	(1,677)	(1,766)	(1,732)	(1,117)
Loss before income taxes	(10,810)	(50,723)	(34,190)	(56,505)
Depreciation and amortization expense	24,351	25,581	49,344	51,219
ACI On Premise [Member]
Segment Reporting Information [Line Items]
Revenues	121,395	127,194	226,425	259,102
ACI On Demand [Member]
Segment Reporting Information [Line Items]
Revenues	113,600	113,405	217,880	212,959
Operating Segments [Member] | ACI On Premise [Member]
Segment Reporting Information [Line Items]
Revenues	121,395	127,194	226,425	259,102
Segment Adjusted EBITDA	54,760	62,527	93,658	130,922
Depreciation and amortization expense	2,849	3,333	5,824	6,594
Operating Segments [Member] | ACI On Demand [Member]
Segment Reporting Information [Line Items]
Revenues	113,600	113,405	217,880	212,959
Segment Adjusted EBITDA	(3,364)	(546)	(7,597)	(7,553)
Depreciation and amortization expense	7,826	9,009	15,562	17,397
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization expense	$ 13,676	$ 13,239	$ 27,958	$ 27,228