Notes Receivable - Loans Receivable on Real Estate (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Receivables [Abstract]
Balance at January 1	$ 52,444	$ 72,218
Additions:
Interest	0	810
Accretion of discount	730	689
Deductions:
Payments of principal and interest	(6,289)	(347)
Other	0	(20,550)
Balance at September 30	$ 46,885	$ 52,820