Common Shares and Preferred Shares Stock Subscription (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2012 Rate	Dec. 31, 2012 Rate
Stock subscription offering [Abstract]
Stock subscription offering, subscription price	$ 19.70	$ 19.70
Stock subscription offering, number of shares subscribed		637,714
stock subscription offering, value of shares subscribed		$ 12,563
Stock subscription offering, minimum financed amount	5	5
Stock subscription offering, down payment	10.00%	10.00%
Stock subscription offering, term		7 years
Stock subscription offering interest rate		2.00%
Stock subscription offering, minimum amount to receive right	$ 5	$ 5
stock subscription offering, number of shares purchased to receive one right		3
Stock subscription offering, number of rights issued	211,800
Stock subscription offering, portion exercisable per year		14.29%
Stock subscription offering, right expiration term		P7Y