CONDENSED CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Revenues	$ 331,361,000	$ 307,971,000	$ 643,775,000	$ 606,475,000
Operating expenses:
Cost of revenues	88,333,000	88,139,000	177,861,000	178,897,000
Research and development	43,612,000	39,439,000	84,263,000	78,382,000
Selling, general and administrative	97,272,000	103,465,000	191,183,000	215,486,000
Amortization of intangible assets	945,000	1,202,000	1,882,000	2,998,000
Restructuring and impairment charges	0	0	0	3,104,000
Unallocated gain on sale of product line assets	0	0	(7,334,000)	0
Total operating expenses	230,162,000	232,245,000	447,855,000	478,867,000
Operating income	101,199,000	75,726,000	195,920,000	127,608,000
Interest expense, net	(9,943,000)	(11,254,000)	(19,584,000)	(21,022,000)
Other income (expense), net	568,000	(2,008,000)	3,448,000	(2,227,000)
Income before income taxes	91,824,000	62,464,000	179,784,000	104,359,000
Income tax provision (benefit)	23,150,000	4,176,000	24,618,000	(8,850,000)
Net income	68,674,000	58,288,000	155,166,000	113,209,000
Other comprehensive gain (loss):
Foreign currency translation adjustments	(1,846,000)	(19,056,000)	15,202,000	(4,964,000)
Comprehensive income	$ 66,828,000	$ 39,232,000	$ 170,368,000	$ 108,245,000
Earnings per share:
Basic (in dollars per share)	$ 2.36	$ 2.00	$ 5.33	$ 3.89
Diluted (in dollars per share)	$ 2.33	$ 1.94	$ 5.23	$ 3.76
Shares used in computing earnings per share:
Basic (in shares)	29,087	29,194	29,107	29,109
Diluted (in shares)	29,531	29,985	29,660	30,076
Transactional and Maintenance
Revenues	$ 280,919,000	$ 240,702,000	$ 533,069,000	$ 461,076,000
Technology Service
Revenues	37,794,000	47,905,000	79,219,000	91,930,000
License
Revenues	$ 12,648,000	$ 19,364,000	$ 31,487,000	$ 53,469,000