XML 35 R32.htm IDEA: XBRL DOCUMENT v2.4.1.9
Accounting Policies - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2014
Dec. 31, 2013
Mar. 31, 2013
Accounting Policies [Line Items]      
Debt discount $ 1,267us-gaap_DebtInstrumentUnamortizedDiscount   $ 450us-gaap_DebtInstrumentUnamortizedDiscount
Accretion of debt discount 1,267posc_DebtInstrumentUnamortizedDiscountCurrent 1,328posc_DebtInstrumentUnamortizedDiscountCurrent  
Embedded Derivative Financial Instruments      
Accounting Policies [Line Items]      
Debt discount $ 0us-gaap_DebtInstrumentUnamortizedDiscount
/ us-gaap_DebtInstrumentAxis
= us-gaap_EmbeddedDerivativeFinancialInstrumentsMember
  $ 0us-gaap_DebtInstrumentUnamortizedDiscount
/ us-gaap_DebtInstrumentAxis
= us-gaap_EmbeddedDerivativeFinancialInstrumentsMember