Going Concern - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Going Concern [Line Items]
Accumulated deficit	$ 124,293,000	$ 123,432,000
Total stockholders' deficit	(12,102,000)us-gaap_StockholdersEquity	(11,241,000)us-gaap_StockholdersEquity
Cash and cash equivalents	1,178,000	1,744,000	40,000	243,000
Accounts payable, trade and accrued liabilities	1,089,000	1,401,000
Working capital balance	$ 6,473,000posc_WorkingCapitalBalance

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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