Schedule of Stockholders' Equity Note, Warrants or Rights Issued on August 09, 2012 (Details) (USD $)	3 Months Ended
Feb. 28, 2013
Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 1	3.63%
Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 2	0.00%
Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 3	0.00%
Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 4	183.31%
Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 5	0.20
Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 6	$ 75,013

Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 5

No definition available.

Name:	sdev_ScheduleOfStockholdersaposEquityNoteWarrantsOrRightsIssuedOnAugustZeroNineTwoZeroOneTwoZeroOneThreeNineSevenOneEightFourFiveCxTGSevenOneSFourTXdFour
Namespace Prefix:	sdev_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 6

No definition available.

Name:	sdev_ScheduleOfStockholdersaposEquityNoteWarrantsOrRightsIssuedOnAugustZeroNineTwoZeroOneTwoZeroOneThreeNineSevenOneEightFourFivedxdHgmMCNinetsOne
Namespace Prefix:	sdev_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 2

No definition available.

Name:	sdev_ScheduleOfStockholdersaposEquityNoteWarrantsOrRightsIssuedOnAugustZeroNineTwoZeroOneTwoZeroOneThreeNineSevenOneEightFourFiveHqgZOnexSevenQThreeZerovz
Namespace Prefix:	sdev_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 4

No definition available.

Name:	sdev_ScheduleOfStockholdersaposEquityNoteWarrantsOrRightsIssuedOnAugustZeroNineTwoZeroOneTwoZeroOneThreeNineSevenOneEightFourFivelbRNineOneOnexQvEightRx
Namespace Prefix:	sdev_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 3

No definition available.

Name:	sdev_ScheduleOfStockholdersaposEquityNoteWarrantsOrRightsIssuedOnAugustZeroNineTwoZeroOneTwoZeroOneThreeNineSevenOneEightFourFiveSevensOneGPFCZerozEightDg
Namespace Prefix:	sdev_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Stock Purchase Warrants Schedule Of Stockholders' Equity Note, Warrants Or Rights Issued On August 09, 2012 1

No definition available.

Name:	sdev_ScheduleOfStockholdersaposEquityNoteWarrantsOrRightsIssuedOnAugustZeroNineTwoZeroOneTwoZeroOneThreeNineSevenOneEightFourFiveZeroKlfPKTwonFourNBM
Namespace Prefix:	sdev_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration