Receivables - Receivables (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 3,499	$ 19,051
Allowance for bad debts	(26)	(26)
Receivables, net	3,473	19,025
Funds held by qualified intermediary
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	14,703
Receivables and accrued interest
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 1,753	$ 2,218
Notes receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average interest rates	12.52%	11.31%
Total	$ 1,746	$ 2,130