Selected Segment Financial Data, Revenues and Operating Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 231,462	$ 226,066
Depreciation and amortization expense	25,638	26,512
Stock-based compensation expense	6,297	9,711
Operating income (loss)	3,623	136,712
Operating Segments [Member] | ACI On Premise [Member]
Segment Reporting Information [Line Items]
Revenues	131,908	112,040
Depreciation and amortization expense	3,261	3,915
Stock-based compensation expense	1,216	1,866
Operating income (loss)	63,918	35,581
Operating Segments [Member] | ACI On Demand [Member]
Segment Reporting Information [Line Items]
Revenues	99,554	98,610
Depreciation and amortization expense	8,388	7,422
Stock-based compensation expense	1,214	1,861
Operating income (loss)	(16,609)	(8,822)
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues	0	15,416
Depreciation and amortization expense	13,989	15,175
Stock-based compensation expense	3,867	5,984
Operating income (loss)	$ (43,686)	$ 109,953