Fair Value Measurements - Balance Sheet Items (Details) - USD ($) $ in Thousands	Oct. 01, 2018	Oct. 31, 2019	Oct. 31, 2018	Aug. 30, 2018
Liabilities:
Debt conversion liability		$ 0	$ 164,212	$ 152,100
Fair Value, Measurements, Recurring
Assets:
Total assets measured at fair value		880,638	859,472
Liabilities:
Debt conversion liability			164,212
Total liabilities measured at fair value		24,833	178,343
Fair Value, Measurements, Recurring | Cash equivalents
Assets:
Cash equivalents		759,114	650,609
Fair Value, Measurements, Recurring | Short-term investments
Assets:
Short-term investments		109,940	148,981
Fair Value, Measurements, Recurring | Prepaid expenses and other
Assets:
Prepaid expenses and other		1,570	133
Fair Value, Measurements, Recurring | Long-term investments
Assets:
Long-term investments		10,014	58,970
Fair Value, Measurements, Recurring | Other long-term assets
Assets:
Other long-term assets			779
Fair Value, Measurements, Recurring | Accrued liabilities
Liabilities:
Accrued liabilities		35	3,231
Fair Value, Measurements, Recurring | Debt conversion liability
Liabilities:
Debt conversion liability			164,212
Fair Value, Measurements, Recurring | Other long-term obligations
Liabilities:
Other long-term obligations		24,798	10,900
Fair Value, Measurements, Recurring | Level 1
Assets:
Total assets measured at fair value		759,114	590,684
Liabilities:
Debt conversion liability			0
Total liabilities measured at fair value		0	0
Fair Value, Measurements, Recurring | Level 1 | Cash equivalents
Assets:
Cash equivalents		759,114	590,684
Fair Value, Measurements, Recurring | Level 1 | Short-term investments
Assets:
Short-term investments		0	0
Fair Value, Measurements, Recurring | Level 1 | Prepaid expenses and other
Assets:
Prepaid expenses and other		0	0
Fair Value, Measurements, Recurring | Level 1 | Long-term investments
Assets:
Long-term investments		0	0
Fair Value, Measurements, Recurring | Level 1 | Other long-term assets
Assets:
Other long-term assets			0
Fair Value, Measurements, Recurring | Level 1 | Accrued liabilities
Liabilities:
Accrued liabilities		0	0
Fair Value, Measurements, Recurring | Level 1 | Debt conversion liability
Liabilities:
Debt conversion liability			0
Fair Value, Measurements, Recurring | Level 1 | Other long-term obligations
Liabilities:
Other long-term obligations		0	0
Fair Value, Measurements, Recurring | Level 2
Assets:
Total assets measured at fair value		121,524	268,788
Liabilities:
Debt conversion liability			164,212
Total liabilities measured at fair value		21,128	167,443
Fair Value, Measurements, Recurring | Level 2 | Cash equivalents
Assets:
Cash equivalents		0	59,925
Fair Value, Measurements, Recurring | Level 2 | Short-term investments
Assets:
Short-term investments		109,940	148,981
Fair Value, Measurements, Recurring | Level 2 | Prepaid expenses and other
Assets:
Prepaid expenses and other		1,570	133
Fair Value, Measurements, Recurring | Level 2 | Long-term investments
Assets:
Long-term investments		10,014	58,970
Fair Value, Measurements, Recurring | Level 2 | Other long-term assets
Assets:
Other long-term assets			779
Fair Value, Measurements, Recurring | Level 2 | Accrued liabilities
Liabilities:
Accrued liabilities		35	3,231
Fair Value, Measurements, Recurring | Level 2 | Debt conversion liability
Liabilities:
Debt conversion liability			164,212
Fair Value, Measurements, Recurring | Level 2 | Other long-term obligations
Liabilities:
Other long-term obligations		21,093	0
Fair Value, Measurements, Recurring | Level 3
Assets:
Total assets measured at fair value		0	0
Liabilities:
Debt conversion liability			0
Total liabilities measured at fair value		3,705	10,900
Fair Value, Measurements, Recurring | Level 3 | Cash equivalents
Assets:
Cash equivalents		0	0
Fair Value, Measurements, Recurring | Level 3 | Short-term investments
Assets:
Short-term investments		0	0
Fair Value, Measurements, Recurring | Level 3 | Prepaid expenses and other
Assets:
Prepaid expenses and other		0	0
Fair Value, Measurements, Recurring | Level 3 | Long-term investments
Assets:
Long-term investments		0	0
Fair Value, Measurements, Recurring | Level 3 | Other long-term assets
Assets:
Other long-term assets			0
Fair Value, Measurements, Recurring | Level 3 | Accrued liabilities
Liabilities:
Accrued liabilities		0	0
Fair Value, Measurements, Recurring | Level 3 | Debt conversion liability
Liabilities:
Debt conversion liability			0
Fair Value, Measurements, Recurring | Level 3 | Other long-term obligations
Liabilities:
Other long-term obligations		$ 3,705	$ 10,900
DonRiver
Liabilities:
Contingent consideration agreement term	3 years