Per Share Amounts and Common Shares Outstanding stock subscription (Details) (USD $)	6 Months Ended
	Jun. 30, 2012 Rate
Per Share Amounts and Common Shares Outstanding [Abstract]
Stock subscription offering, subscription price	$ 19.70
Stock subscription offering, minimum financed amount	$ 5,000
Stock subscription offering, down payment	10.00%
Stock subscription offering, term (in years)	7
Stock subscription offering interest rate	2.00%
Stock subscription offering, minimum amount to receive right	$ 5,000
Stock subscription offering, number of shares purchased to receive one right	3
Stock subscription offering, right expiration term (in years)	7
Stock subscription offering, portion exercisable per year	14.29%