Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net sales:
Total net sales	$ 308,124	$ 340,442	$ 918,834	$ 985,747
Cost of sales:
Total cost of sales	92,263	85,915	261,925	245,756
Gross profit	215,861	254,527	656,909	739,991
Operating expenses:
Sales and marketing	109,774	113,922	330,939	352,340
Research and development	70,802	66,558	206,648	200,981
General and administrative	37,431	35,711	92,980	92,639
Total operating expenses	218,007	216,191	630,567	645,960
Gain on sale of business/asset	0	26,842	159,753	26,842
Operating (loss) income	(2,146)	65,178	186,095	120,873
Other Nonoperating Income (Expense) [Abstract]
Other (expense) income	(2,001)	2,249	(2,584)	5,379
Income before income taxes	(4,147)	67,427	183,511	126,252
Provision for income taxes	475	15,783	44,588	22,697
Net (loss) income	$ (4,622)	$ 51,644	$ 138,923	$ 103,555
Basic (loss) earnings per share (in usd per share)	$ (0.04)	$ 0.39	$ 1.06	$ 0.79
Weighted average shares outstanding - basic (in shares)	131,419	131,385	131,017	131,896
Diluted (loss) earnings per share (in usd per share)	$ (0.04)	$ 0.39	$ 1.06	$ 0.78
Weighted average shares outstanding - diluted (in shares)	131,419	131,889	131,671	132,890
Dividends declared per share (in usd per share)	$ 0.26	$ 0.25	$ 0.78	$ 0.75
Product
Net sales:
Total net sales	$ 269,651	$ 305,247	$ 809,890	$ 882,747
Cost of sales:
Total cost of sales	88,370	84,127	254,236	240,056
Software maintenance
Net sales:
Total net sales	38,473	35,195	108,944	103,000
Cost of sales:
Total cost of sales	$ 3,893	$ 1,788	$ 7,689	$ 5,700