Notes Receivable - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Document Period End Date	Mar. 31, 2013
Notes receivable, net	$ 50,263,000		$ 53,172,000
Chattel Loans receivable	30,700,000		32,700,000
Home loans repossessed	599,000	1,887,000
Business Combinations, Acquired Receivables, Current Value	23,800,000
Certain Loans Acquired in Transfer, Accretable Yield			0.210	0.170
Contract receivables	15,600,000		16,100,000
Contract Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, amortization term	4 years
Proceeds from receivables repaid	1,900,000	1,800,000
Additional loan to customers	1,300,000	900,000
Provision for uncollectible receivable	600,000		700,000
Contracts Receivable, yield interest at a stated per annum average	16.00%
Chattel Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Home loans repossessed	600,000	1,900,000
Loans receivable, stated interest yield per annum	7.80%
Notes Receivable Yield Rate	18.20%
Loans receivable, amortization term	14 years
Notes receivable, allowance	400,000	400,000
Proceeds from receivables repaid	1,300,000	1,800,000
Additional loan to customers	$ 200,000	$ 200,000