Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
License		$ 94,230	$ 50,237	$ 67,161	$ 39,577	$ 80,425	$ 57,653	$ 61,377	$ 35,702	$ 251,205	$ 235,157	$ 233,931
Maintenance		63,000	59,262	60,141	59,492	67,421	63,764	62,309	62,499	241,895	255,993	245,954
Services		34,371	25,842	23,110	23,497	29,811	28,194	24,991	22,588	106,820	105,584	122,085
Hosting		117,036	103,360	115,410	110,251	112,567	100,033	106,131	100,684	446,057	419,415	262,958
Total revenues		308,637	238,701	265,822	232,817	290,224	249,644	254,808	221,473	1,045,977	1,016,149	864,928
Operating expenses:
Cost of license	[1]	5,810	5,387	5,939	6,109	6,499	5,433	6,897	5,736	23,245	24,565	25,324
Cost of maintenance, services and hosting	[1]	111,285	104,272	120,484	113,013	104,390	105,319	112,595	107,887	449,054	430,191	318,515
Research and development		33,285	36,123	39,425	37,091	31,554	36,321	38,876	37,456	145,924	144,207	142,557
Selling and marketing		40,747	28,451	31,298	28,911	29,053	27,078	28,007	27,909	129,407	112,047	99,828
General and administrative		20,552	20,284	25,008	21,575	19,938	25,329	24,682	25,116	87,419	95,065	99,300
Depreciation and amortization		22,985	20,298	20,004	19,693	19,519	18,295	17,010	17,078	82,980	71,902	56,356
Total operating expenses		234,664	214,815	242,158	226,392	210,953	217,775	228,067	221,182	918,029	877,977	741,880
Operating income		73,973	23,886	23,664	6,425	79,271	31,869	26,741	291	127,948	138,172	123,048
Other income (expense):
Interest expense		(10,198)	(9,728)	(10,505)	(10,941)	(10,818)	(10,416)	(9,329)	(9,175)	(41,372)	(39,738)	(27,221)
Interest income		132	94	58	102	143	98	135	199	386	575	659
Other, net		(1,284)	4,314	19,659	3,722	1,104	3,614	(3,901)	(1,057)	26,411	(240)	(3,327)
Total other income (expense)		(11,350)	(5,320)	9,212	(7,117)	(9,571)	(6,704)	(13,095)	(10,033)	(14,575)	(39,403)	(29,889)
Income (loss) before income taxes		62,623	18,566	32,876	(692)	69,700	25,165	13,646	(9,742)	113,373	98,769	93,159
Income tax expense (benefit)		18,856	3,786	5,825	(530)	23,334	9,433	2,409	(3,967)	27,937	31,209	29,291
Net income (loss)		$ 43,767	$ 14,780	$ 27,051	$ (162)	$ 46,366	$ 15,732	$ 11,237	$ (5,775)	$ 85,436	$ 67,560	$ 63,868
Earnings (loss) per share
Basic		$ 0.37	$ 0.13	$ 0.23	$ 0.00	$ 0.40	$ 0.14	$ 0.10	$ (0.05)	$ 0.73	$ 0.59	$ 0.54
Diluted		$ 0.36	$ 0.12	$ 0.23	$ 0.00	$ 0.40	$ 0.14	$ 0.10	$ (0.05)	$ 0.72	$ 0.58	$ 0.53

[1] The cost of software license fees excludes charges for depreciation but includes amortization of purchased and developed software for resale. The cost of maintenance, services and hosting fees excludes charges for depreciation.