Basis of Presentation and Consolidation - Schedule of Non-Controlling Interest in Subsidiary (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Minority Interest [Line Items]
Balance at the beginning of the period	$ (1,539)	$ 239
Net loss attributable to Silver Creek	(467)	(185)
Balance at the end of the period	(1,406)	$ 54
Series C Preferred Stock [Member]
Minority Interest [Line Items]
Issuance of Silver Creek Series C preferred stock	$ 600