Revenues, Expenses and Operating Income by Reporting Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Software license	$ 19,130	$ 16,945	$ 58,202	$ 52,041
Services	112,549	98,518	321,096	278,950
Hardware and other	10,625	10,145	35,638	30,710
Total revenue	142,304	125,608	414,936	361,701
Cost of revenue	58,096	53,864	175,097	153,986
Operating expenses	38,551	34,568	112,265	105,011
Depreciation and amortization	1,977	1,675	5,656	4,652
Total costs and expenses	98,624	90,107	293,018	263,649
Operating income	43,680	35,501	121,918	98,052
Americas
Segment Reporting Information [Line Items]
Software license	16,977	15,650	49,754	41,606
Services	93,513	78,452	264,288	223,240
Hardware and other	9,628	9,317	33,189	28,561
Total revenue	120,118	103,419	347,231	293,407
Cost of revenue	47,305	42,970	140,957	121,004
Operating expenses	34,630	30,168	98,424	90,154
Depreciation and amortization	1,776	1,531	5,047	4,239
Total costs and expenses	83,711	74,669	244,428	215,397
Operating income	36,407	28,750	102,803	78,010
EMEA
Segment Reporting Information [Line Items]
Software license	1,347	589	6,995	6,660
Services	14,700	13,139	43,404	37,854
Hardware and other	782	525	1,910	1,329
Total revenue	16,829	14,253	52,309	45,843
Cost of revenue	7,891	7,312	25,437	22,339
Operating expenses	2,893	3,242	10,564	11,361
Depreciation and amortization	136	82	361	229
Total costs and expenses	10,920	10,636	36,362	33,929
Operating income	5,909	3,617	15,947	11,914
APAC
Segment Reporting Information [Line Items]
Software license	806	706	1,453	3,775
Services	4,336	6,927	13,404	17,856
Hardware and other	215	303	539	820
Total revenue	5,357	7,936	15,396	22,451
Cost of revenue	2,900	3,582	8,703	10,643
Operating expenses	1,028	1,158	3,277	3,496
Depreciation and amortization	65	62	248	184
Total costs and expenses	3,993	4,802	12,228	14,323
Operating income	$ 1,364	$ 3,134	$ 3,168	$ 8,128