Investment in Non-Consolidated Joint Venture - Components of Joint Venture Investment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Beginning Balance	$ 38,462
Capital contributions		$ 1,999
Our share of cumulative earnings	5,938	5,001	$ 831
Ending Balance	40,694	38,462
Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	38,462	34,331	35,595
Capital contributions		1,999
Dividends received		(2,868)	(2,538)
Our share of cumulative earnings	6,427	5,440	1,646
Dividends declared and paid by joint venture	(3,706)
Accretion of basis difference from purchase accounting	(489)	(440)	(372)
Ending Balance	$ 40,694	$ 38,462	$ 34,331