Cash, Equivalents and Marketable Securities - Additional Information (Detail) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Schedule Of Investments [Abstract]
Cash, equivalents and marketable securities, including long term bank certificates of deposits, and investments, total	$ 127,900,000	$ 145,500,000
Restricted certificates of deposit	$ 250,000	$ 250,000
None of securities in a continuous unrealized loss position, period	One year

Cash, cash equivalents and marketable securities, including long term bank certificates of deposits, and investments, total.

No definition available.

Name:	sppi_CashAndCashEquivalentMarketableSecurities
Namespace Prefix:	sppi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant