Segment Reporting Information by Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenue
Services	$ 67,350	$ 72,034	$ 196,671	$ 217,143
Systems	27,982	23,999	69,972	66,526
Total revenue	95,332	96,033	266,643	283,669
Direct costs of revenue
Direct cost of services	36,758	39,573	107,357	121,096
Direct cost of systems revenue	22,668	20,677	50,346	55,402
Total direct cost of revenue	59,426	60,250	157,703	176,498
Gross profit
Services gross profit	30,592	32,461	89,314	96,047
Systems gross profit	5,314	3,322	19,626	11,124
Total gross profit	35,906	35,783	108,940	107,171
Research and development expense	(10,473)	(7,898)	(32,121)	(25,745)
Sales and marketing expense	(6,607)	(6,684)	(19,855)	(22,445)
General and administrative expense	(11,127)	(13,824)	(35,951)	(42,552)
Depreciation and amortization of property and equipment	(3,208)	(3,768)	(9,977)	(10,885)
Amortization of acquired intangible assets	(950)	(1,142)	(2,848)	(3,427)
Interest expense	(2,007)	(2,173)	(6,237)	(6,126)
Amortization of deferred financing fees	(203)	(1,538)	(583)	(3,275)
Loss on early retirement of debt		(151)		(151)
Other income (expense), net	(688)	46	(551)	(62)
Net income (loss) before income taxes	643	(1,349)	817	(7,497)
Income tax (expense) benefit	(2,607)	1,194	(2,200)	4,642
Net loss	(1,964)	(155)	(1,383)	(2,855)
Commercial Segment
Revenue
Services	42,512	37,217	115,102	112,734
Systems	4,101	6,502	18,773	15,265
Total revenue	46,613	43,719	133,875	127,999
Direct costs of revenue
Direct cost of services	16,695	15,855	45,183	47,340
Direct cost of systems revenue	3,082	5,478	9,346	13,195
Total direct cost of revenue	19,777	21,333	54,529	60,535
Gross profit
Services gross profit	25,817	21,362	69,919	65,394
Systems gross profit	1,019	1,024	9,427	2,070
Total gross profit	26,836	22,386	79,346	67,464
Government Segment
Revenue
Services	24,838	34,817	81,569	104,409
Systems	23,881	17,497	51,199	51,261
Total revenue	48,719	52,314	132,768	155,670
Direct costs of revenue
Direct cost of services	20,063	23,718	62,174	73,756
Direct cost of systems revenue	19,586	15,199	41,000	42,207
Total direct cost of revenue	39,649	38,917	103,174	115,963
Gross profit
Services gross profit	4,775	11,099	19,395	30,653
Systems gross profit	4,295	2,298	10,199	9,054
Total gross profit	$ 9,070	$ 13,397	$ 29,594	$ 39,707