Fair Value Measurements (Details) - USD ($) $ in Thousands	9 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Sep. 30, 2016
Financial assets:
Cash equivalents			$ 60,118	$ 60,139
Available-for-sale Securities			50,189	49,616
Forward contracts			4,802	260
Financial assets, fair value			115,109	110,015
Financial liabilities:
Contingent consideration related to acquisitions	$ 19,570		7,862	19,570
Forward contracts			4,525	3,170
Liabilities, Fair Value Disclosure, Recurring			12,387	22,740
Business Combination. Contingent Consideration [Roll Forward]
Balance, October 1, 2016	19,570
Addition to contingent consideration		$ 16,900
Payment of contingent consideration	(12,100)	(11,500)
Balance, July 1, 2017	7,862
Level 1 [Member]
Financial assets:
Cash equivalents			60,118	60,139
Financial assets, fair value			107,472	94,740
Financial liabilities:
Contingent consideration related to acquisitions	0		0	0
Forward contracts			0	0
Liabilities, Fair Value Disclosure, Recurring			0	0
Business Combination. Contingent Consideration [Roll Forward]
Balance, October 1, 2016	0
Balance, July 1, 2017	0
Level 2 [Member]
Financial assets:
Forward contracts			4,802	260
Financial assets, fair value			7,637	15,275
Financial liabilities:
Contingent consideration related to acquisitions	0		0	0
Forward contracts			4,525	3,170
Liabilities, Fair Value Disclosure, Recurring			4,525	3,170
Business Combination. Contingent Consideration [Roll Forward]
Balance, October 1, 2016	0
Balance, July 1, 2017	0
Level 3 [Member]
Financial liabilities:
Contingent consideration related to acquisitions	19,570	13,000	7,862	19,570
Forward contracts			0	0
Liabilities, Fair Value Disclosure, Recurring			7,862	19,570
Business Combination. Contingent Consideration [Roll Forward]
Balance, October 1, 2016	19,570	13,000
Change in present value of contingent consideration	392	1,097
Payment of contingent consideration	(12,100)	(11,500)
Balance, July 1, 2017	7,862	19,497
ThingWorx | Level 3 [Member]
Financial liabilities:
Contingent consideration related to acquisitions		9,000
Business Combination. Contingent Consideration [Roll Forward]
Balance, October 1, 2016		9,000
Addition to contingent consideration		0
Change in present value of contingent consideration		0
Payment of contingent consideration		(9,000)
Balance, July 1, 2017		0
ColdLight | Level 3 [Member]
Financial liabilities:
Contingent consideration related to acquisitions	2,500	4,000	0	2,500
Business Combination. Contingent Consideration [Roll Forward]
Balance, October 1, 2016	2,500	4,000
Addition to contingent consideration		0
Change in present value of contingent consideration	0	1,000
Payment of contingent consideration	(2,500)	(2,500)
Balance, July 1, 2017	0	2,500
Kepware
Financial liabilities:
Contingent consideration related to acquisitions	7,900		7,900
Business Combination. Contingent Consideration [Roll Forward]
Balance, July 1, 2017	7,900
Kepware | Level 3 [Member]
Financial liabilities:
Contingent consideration related to acquisitions	17,070	0	7,862	17,070
Business Combination. Contingent Consideration [Roll Forward]
Balance, October 1, 2016	17,070	0
Addition to contingent consideration		16,900
Change in present value of contingent consideration	392	97
Payment of contingent consideration	(9,600)	0
Balance, July 1, 2017	$ 7,862	$ 16,997
Certificates of deposit
Financial assets:
Available-for-sale Securities			441	681
Certificates of deposit | Level 2 [Member]
Financial assets:
Available-for-sale Securities			441	681
Commercial paper
Financial assets:
Available-for-sale Securities				11,925
Commercial paper | Level 2 [Member]
Financial assets:
Available-for-sale Securities				11,925
Corporate notes/bonds
Financial assets:
Available-for-sale Securities			47,354	34,601
Corporate notes/bonds | Level 1 [Member]
Financial assets:
Available-for-sale Securities			47,354	34,601
U.S. government agency securities
Financial assets:
Available-for-sale Securities			2,394	2,409
U.S. government agency securities | Level 2 [Member]
Financial assets:
Available-for-sale Securities			$ 2,394	$ 2,409