Revolving Line of Credit (Details) (USD $) In Millions, unless otherwise specified	2 Months Ended	7 Months Ended	10 Months Ended	12 Months Ended
	Feb. 28, 2009	Jul. 31, 2010	Oct. 31, 2011	Dec. 31, 2012	Aug. 02, 2007
Summary of the key terms in effect for the line of credit
Agreement / Amendment Date	Feb. 28, 2009	Jul. 31, 2010	Oct. 31, 2011	Dec. 31, 2012
Total Commitment under Credit Facility	$ 85	$ 100	$ 100	$ 150	$ 30
Rate options	Prime plus 1.75% or LIBOR plus 3.75%	Prime plus 1.25% or LIBOR plus 3.25%	Prime plus 0.75% or LIBOR plus 2.75%	Base plus 0.75% or LIBOR plus 2.5%
Facility Expiration	Aug. 31, 2010	Aug. 31, 2013	Aug. 31, 2014	Dec. 31, 2016
Minimum [Member]
Summary of the key terms in effect for the line of credit
Total Commitment under Credit Facility				$ 100
Minimum Rate	5.00%			2.96%