Debt MIF Warehousing Agreement (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Maximum Borrowing Availabilitiy under Sterling Warehouse Line	$ 15,000
Maximum Borrowing Availability under all Credit Lines	95,000
Notes Payable - Financial Services	53,126	67,957
Third Amendment [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	70,000
Aggreate Maximum Principal Amount Permitted to be Outstanding Under All Warehousing Credit Lines	100,000
LIBOR basis points	225
Debt Instrument, Basis Spread on Variable Rate	3.50%
Amended and Restated [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	80,000
Aggreate Maximum Principal Amount Permitted to be Outstanding Under All Warehousing Credit Lines	$ 125,000
LIBOR basis points	275
Debt Instrument, Basis Spread on Variable Rate	3.50%