Summary of Significant Accounting Policies and Use of Estimates - Additional Information (Detail)	12 Months Ended
Dec. 31, 2016
Accounting Policies [Abstract]
Number of months customers are allowed to return products	6 months
Cash and equivalents maturities period	3 months

Number Of Months After Product Expiration During Which Customer Can Return Product

No definition available.

Name:	sppi_NumberOfMonthsAfterProductExpirationDuringWhichCustomerCanReturnProduct
Namespace Prefix:	sppi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration