Stock based compensation (Details 2) (Restricted Stock Units (RSUs) [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Restricted Stock Units (RSUs) [Member]
Compensation Expense Schedule Assuming all RSUs Vest
Compensation expense 2013	$ 125
Compensation expense 2014	125
Compensation expense 2015	95
Compensation expense 2016	80
Compensation expense 2017	40
Compensation expense, total	$ 465

The total of future share-based compensation of vested RSUs.

No definition available.

Name:	PSBQ_CompensationExpenseFutureMinimumPaymentsDue
Namespace Prefix:	PSBQ_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Share-based compensation expense in excess of one year, within one year of the balance sheet date relating to restricted shares that vest to employees.

+ References

No definition available.

+ Details

Name:	PSBQ_CompensationExpenseFutureMinimumPaymentsDueCurrent
Namespace Prefix:	PSBQ_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Share-based compensation expense within fifth year of the balance sheet date relating to restricted shares that vest to employees.

+ References

No definition available.

+ Details

Name:	PSBQ_CompensationExpenseFutureMinimumPaymentsDueInFiveYears
Namespace Prefix:	PSBQ_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Share-based compensation expense within fourth year of the balance sheet date relating to restricted shares that vest to employees.

+ References

No definition available.

+ Details

Name:	PSBQ_CompensationExpenseFutureMinimumPaymentsDueInFourYears
Namespace Prefix:	PSBQ_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Share-based compensation expense within third year of the balance sheet date relating to restricted shares that vest to employees.

+ References

No definition available.

+ Details

Name:	PSBQ_CompensationExpenseFutureMinimumPaymentsDueInThreeYears
Namespace Prefix:	PSBQ_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Share-based compensation expense within second year of the balance sheet date relating to restricted shares that vest to employees.

+ References

No definition available.

+ Details

Name:	PSBQ_CompensationExpenseFutureMinimumPaymentsDueInTwoYears
Namespace Prefix:	PSBQ_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	PSBQ_CompensationExpenseScheduleAssumingAllRsusVestAbstract
Namespace Prefix:	PSBQ_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration