Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net sales:
Total net sales	$ 301,329	$ 334,231	$ 610,709	$ 645,305
Cost of sales:
Total cost of sales	85,901	83,766	169,662	159,841
Gross profit	215,428	250,465	441,047	485,464
Operating expenses:
Sales and marketing	105,419	120,868	221,165	238,419
Research and development	64,225	68,257	135,846	134,423
General and administrative	29,369	29,044	55,549	56,927
Total operating expenses	199,013	218,169	412,560	429,769
Gain on sale of business	0	0	159,753	0
Operating income	16,415	32,296	188,240	55,695
Other Nonoperating Income (Expense) [Abstract]
Other (expense) income	(1,143)	555	(583)	3,131
Income before income taxes	15,272	32,851	187,657	58,826
Provision for income taxes	4,383	4,159	44,113	6,914
Net income	$ 10,889	$ 28,692	$ 143,544	$ 51,912
Basic earnings per share (in dollars per share)	$ 0.08	$ 0.22	$ 1.10	$ 0.39
Weighted average shares outstanding - basic (in shares)	131,014	132,062	130,813	132,156
Diluted earnings per share (in dollars per share)	$ 0.08	$ 0.22	$ 1.09	$ 0.39
Weighted average shares outstanding - diluted (in shares)	131,602	132,973	131,499	133,172
Dividends declared per share (in dollars per share)	$ 0.26	$ 0.25	$ 0.52	$ 0.50
Product
Net sales:
Total net sales	$ 266,261	$ 299,798	$ 540,239	$ 577,500
Cost of sales:
Total cost of sales	83,795	81,741	165,866	155,929
Software maintenance
Net sales:
Total net sales	35,068	34,433	70,470	67,805
Cost of sales:
Total cost of sales	$ 2,106	$ 2,025	$ 3,796	$ 3,912