Investment in Non-Consolidated Joint Venture - Components of Joint Venture Investment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Equity Method Investments [Line Items]
Beginning Balance			$ 38,462
Our share of cumulative earnings	$ 1,427	$ 621	4,170	$ 2,503
Ending Balance	38,925		38,925
Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance			38,462
Our share of cumulative earnings			4,545
Dividends declared and paid by joint venture	(3,707)		(3,707)
Accretion of basis difference from purchase accounting			(375)
Ending Balance	$ 38,925		$ 38,925