CONDENSED CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Revenues		$ 278,234	$ 256,260	$ 540,490	$ 488,621
Operating expenses:
Cost of revenues	[1]	85,568	79,493	161,634	153,925
Research and development		37,684	32,519	73,110	61,493
Selling, general and administrative	[1]	104,930	96,125	205,188	186,467
Amortization of intangible assets	[1]	1,503	1,684	3,005	3,472
Total operating expenses		229,685	209,821	442,937	405,357
Operating income		48,549	46,439	97,553	83,264
Interest expense, net		(10,008)	(7,116)	(19,684)	(13,576)
Other income (expense), net		1,433	(161)	(739)	352
Income before income taxes		39,974	39,162	77,130	70,040
Provision for income taxes		6,593	7,993	3,742	5,992
Net income		33,381	31,169	73,388	64,048
Other comprehensive income (loss):
Foreign currency translation adjustments		2,925	9,125	(340)	12,196
Comprehensive income		$ 36,306	$ 40,294	$ 73,048	$ 76,244
Earnings per share:
Basic (in dollars per share)		$ 1.15	$ 1.04	$ 2.53	$ 2.13
Diluted (in dollars per share)		$ 1.10	$ 1.00	$ 2.42	$ 2.04
Shares used in computing earnings per share:
Basic (in shares)		29,074	29,985	29,017	30,032
Diluted (in shares)		30,259	31,300	30,297	31,431
Transactional and Maintenance
Revenues		$ 211,779	$ 192,791	$ 405,972	$ 363,194
Technology Service
Revenues		50,555	46,731	91,363	89,859
License
Revenues		$ 15,900	$ 16,738	$ 43,155	$ 35,568

[1] Cost of revenues and selling, general and administrative expenses exclude the amortization of intangible assets. See Note 4.