Fair Value Measurements (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Oct. 31, 2018	Aug. 30, 2018
Assets:
U.S. government obligations	$ 119,954
Liabilities:
Debt conversion liability	0	$ 164,212	$ 152,100
Contingent Consideration	4,372	0
Fair Value, Measurements, Recurring
Assets:
Money market funds	759,114	590,684
U.S. government obligations	119,954	197,988
Commercial paper		69,888
Foreign currency forward contracts	1,570	133
Forward starting interest rate swaps		779
Total assets measured at fair value	880,638	859,472
Liabilities:
Debt conversion liability		164,212
Contingent Consideration	3,705	10,900
Total liabilities measured at fair value	24,833	178,343
Level 1 | Fair Value, Measurements, Recurring
Assets:
Money market funds	759,114	590,684
U.S. government obligations	0	0
Commercial paper		0
Foreign currency forward contracts	0	0
Forward starting interest rate swaps		0
Total assets measured at fair value	759,114	590,684
Liabilities:
Debt conversion liability		0
Contingent Consideration	0	0
Total liabilities measured at fair value	0	0
Level 2 | Fair Value, Measurements, Recurring
Assets:
Money market funds	0	0
U.S. government obligations	119,954	197,988
Commercial paper		69,888
Foreign currency forward contracts	1,570	133
Forward starting interest rate swaps		779
Total assets measured at fair value	121,524	268,788
Liabilities:
Debt conversion liability		164,212
Contingent Consideration	0	0
Total liabilities measured at fair value	21,128	167,443
Level 3 | Fair Value, Measurements, Recurring
Assets:
Money market funds	0	0
U.S. government obligations	0	0
Commercial paper		0
Foreign currency forward contracts	0	0
Total assets measured at fair value	0	0
Liabilities:
Debt conversion liability		0
Contingent Consideration	3,705	10,900
Total liabilities measured at fair value	3,705	10,900
Foreign currency forward contracts | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	35	3,231
Foreign currency forward contracts | Level 1 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	0	0
Foreign currency forward contracts | Level 2 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	35	3,231
Foreign currency forward contracts | Level 3 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	0	$ 0
Forward starting interest rate swaps | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	21,093
Forward starting interest rate swaps | Level 1 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	0
Forward starting interest rate swaps | Level 2 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	21,093
Forward starting interest rate swaps | Level 3 | Fair Value, Measurements, Recurring
Liabilities:
Derivative liability	$ 0