Condensed Consolidated Statements Of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Revenue	$ 748,697	$ 742,365	$ 1,467,840	$ 1,439,557
Cost of net revenues:
Total cost of net revenues	110,479	108,749	217,952	217,035
Gross margin	638,218	633,616	1,249,888	1,222,522
Operating expenses:
Research and development	134,029	112,943	264,292	211,493
Sales, marketing and services	298,429	286,730	573,084	537,943
General and administrative	81,162	77,340	158,709	141,067
Amortization of other intangible assets	3,205	4,019	6,734	7,685
Restructuring	4,311	7,437	7,143	13,624
Total operating expenses	521,136	488,469	1,009,962	911,812
Income from operations	117,082	145,147	239,926	310,710
Interest income	3,870	9,402	13,544	18,133
Interest expense	(10,289)	(20,542)	(28,322)	(40,878)
Other (expense) income, net	(3,420)	(2,537)	279	(5,549)
Income before income taxes	107,243	131,470	225,427	282,416
Income tax expense	13,748	24,637	21,584	31,324
Net income	$ 93,495	$ 106,833	$ 203,843	$ 251,092
Earnings per share:
Basic earnings per share (in dollars per share)	$ 0.71	$ 0.79	$ 1.55	$ 1.82
Diluted earnings per share (in dollars per share)	$ 0.70	$ 0.73	$ 1.48	$ 1.72
Weighted average shares outstanding:
Basic (in shares)	131,309	135,993	131,396	137,614
Diluted (in shares)	134,277	145,447	137,635	145,709
Subscription [Member]
Revenues:
Revenue	$ 155,833	$ 110,796	$ 297,439	$ 213,954
Product and License [Member]
Revenues:
Revenue	140,654	192,058	275,676	352,755
Cost of net revenues:
Cost of net revenues	21,878	29,707	47,622	63,579
Support and Services [Member]
Revenues:
Revenue	452,210	439,511	894,725	872,848
Subscription, Support and Service [Member]
Cost of net revenues:
Cost of net revenues	78,817	67,523	150,245	130,908
Product [Member]
Cost of net revenues:
Amortization of product related intangible assets	$ 9,784	$ 11,519	$ 20,085	$ 22,548