Basis of Presentation and Consolidation - Additional Information (Detail)		9 Months Ended
	Aug. 11, 2017 shares	Sep. 30, 2017 shares	Sep. 05, 2017 shares	Dec. 31, 2016 shares
Summary Of Significant Accounting Policies [Line Items]
Reverse stock split description		Reverse Split, every ten shares of common stock issued and outstanding was converted into one share of common stock
Reverse stock split, conversion ratio	0.1
Common stock, shares issued	132,800,000	13,274,000	13,280,000	13,020,000
Common stock, shares outstanding	132,800,000	13,274,000	13,280,000	13,020,000
Common stock, shares authorized	200,000,000	20,000,000	20,000,000	20,000,000
Number of fractional shares issued			0
Preferred stock, shares issued		0	0	0
Preferred stock, shares outstanding		0	0	0
Silver Creek [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Ownership interest percentage held by parent		50.00%