Goodwill and Acquired Intangible Assets (Tables)

12 Months Ended

Sep. 30, 2021

Goodwill And Intangible Assets Disclosure [Abstract]

Schedule of Goodwill and Acquired Intangible Assets

Goodwill and acquired intangible assets consisted of the following:

(in thousands)	September 30, 2021						September 30, 2020
	Gross Carrying Amount		Accumulated Amortization		Net Book Value		Gross Carrying Amount		Accumulated Amortization		Net Book Value
Goodwill (not amortized)					$	2,191,887					$	1,625,786
Intangible assets with finite lives (amortized)(1):
Purchased software	$	483,771	$	338,542	$	145,229	$	443,275	$	309,124	$	134,151
Capitalized software		22,877		22,877		—		22,877		22,877		—
Customer lists and relationships		574,516		350,648		223,868		418,953		322,092		96,861
Trademarks and trade names		26,906		17,036		9,870		22,687		16,129		6,558
Other		4,000		4,000		—		4,017		4,017		—
	$	1,112,070	$	733,103	$	378,967	$	911,809	$	674,239	$	237,570
Total goodwill and acquired intangible assets					$	2,570,854					$	1,863,356

(1) The weighted-average useful lives of purchased software, customer lists and relationships, and trademarks and trade names with a remaining net book value are 10  years, 11 years, and 12 years, respectively.

Schedule of Changes in Goodwill by Reportable Segment

Changes in goodwill presented by reportable segment were as follows:

(in thousands)	Software Products		Professional Services		Total
Balance, September 30, 2019	$	1,196,064	$	42,115	$	1,238,179
Onshape Acquisition		364,910		—		364,910
Other acquisitions		12,262		—		12,262
Foreign currency translation adjustments		10,080		355		10,435
Balance, September 30, 2020	$	1,583,316	$	42,470	$	1,625,786
Arena acquisition		563,620		—		563,620
Other acquisitions		181		400		581
Foreign currency translation adjustments		1,851		49		1,900
Balance, September 30, 2021	$	2,148,968	$	42,919	$	2,191,887

Schedule of Aggregate Amortization Expense for Intangible Assets with Finite Lives

The aggregate amortization expense for intangible assets with finite lives recorded for the years ended September 30, 2021, 2020 and 2019 was reflected in our Consolidated Statements of Operations as follows:

(in thousands)	Year ended September 30,
	2021		2020		2019
Amortization of acquired intangible assets	$	29,396	$	28,713	$	23,841
Cost of software revenue		29,769		27,391		27,307
Total amortization expense	$	59,165	$	56,104	$	51,148