Revolving Credit Facility (Details) (Capital One, National Association [Member], Revolving Credit Facility [Member], USD $) In Millions, unless otherwise specified	0 Months Ended
	Mar. 30, 2012	Dec. 31, 2012
Line of Credit Facility [Line Items]
Maximum capacity on credit facility	$ 40.0
Term of credit facility	36 months
Extension option of credit facility	12 months
Revolving credit facility		20.0
Debt Instrument, Interest Rate, Effective Percentage		2.70%
Line of Credit Facility, Remaining Borrowing Capacity		8.3
LIBOR [Member]
Line of Credit Facility [Line Items]
Spread on variable rate basis	2.50%
Unused capacity commitment fee percentage threshold	50.00%
Maximum [Member]
Line of Credit Facility [Line Items]
Accordion feature of credit facility	$ 150.0
Above Threshold [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Unused capacity fee percentage	0.30%
Below Threshold [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Unused capacity fee percentage	0.20%