Condensed Consolidated Statements Of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Revenues:
Revenue	$ 742,365	$ 693,227	[1]	$ 1,439,557	$ 1,355,904	[1]
Cost of net revenues:
Total cost of net revenues	108,749	109,312		217,035	211,770
Gross margin	633,616	583,915		1,222,522	1,144,134
Operating expenses:
Research and development	112,943	106,696		211,493	209,365
Sales, marketing and services	286,730	268,300		537,943	515,065
General and administrative	77,340	81,146		141,067	157,655
Amortization of other intangible assets	4,019	3,692		7,685	7,338
Restructuring	7,437	2,140		13,624	10,126
Total operating expenses	488,469	461,974		911,812	899,549
Income from operations	145,147	121,941		310,710	244,585
Interest income	9,402	5,560		18,133	11,172
Interest expense	(20,542)	(12,007)		(40,878)	(23,560)
Other (expense) income, net	(2,537)	(1,141)		(5,549)	2,185
Income from continuing operations before income taxes	131,470	114,353		282,416	234,382
Income tax expense	24,637	5,524		31,324	55,228
Income from continuing operations	106,833	108,829		251,092	179,154
(Loss) from discontinued operations, net of income taxes	0	0		0	(42,704)
Net income	$ 106,833	$ 108,829		$ 251,092	$ 136,450
Basic earnings (loss) per share:
Income from continuing operations, basic (in dollars per share)	$ 0.79	$ 0.72		$ 1.82	$ 1.18
(Loss) from discontinued operations, basic (in dollars per share)	0.00	0.00		0.00	(0.28)
Basic earnings per share (in dollars per share)	0.79	0.72		1.82	0.90
Diluted earnings (loss) per share:
Income from continuing operations, diluted (in dollars per share)	0.73	0.70		1.72	1.14
(Loss) from discontinued operations, diluted (in dollars per share)	0.00	0.00		0.00	(0.27)
Diluted earnings per share (in dollars per share)	$ 0.73	$ 0.70		$ 1.72	$ 0.87
Weighted average shares outstanding:
Basic (in shares)	135,993	151,212		137,614	152,247
Diluted (in shares)	145,447	156,036		145,709	157,239
Subscription [Member]
Revenues:
Revenue	$ 110,796	$ 74,596		$ 213,954	$ 143,686
Product and License [Member]
Revenues:
Revenue	192,058	190,376		352,755	361,275
Cost of net revenues:
Cost of net revenues	29,707	32,735		63,579	62,446
Support and Services [Member]
Revenues:
Revenue	439,511	428,255		872,848	850,943
Subscription, Support and Service [Member]
Cost of net revenues:
Cost of net revenues	67,523	64,167		130,908	123,826
Product [Member]
Cost of net revenues:
Amortization of product related intangible assets	$ 11,519	$ 12,410		$ 22,548	$ 25,498

[1] As noted above, prior period amounts have not been adjusted under the modified retrospective method. See Note 2 for further information regarding the Company’s adoption of the revenue recognition standard.