Income Taxes - Schedule of Annual Limitations for Net Operating Losses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary Of Tax Credit Carry Forward And Operating Loss Carry Forwards [Line Items]
Total	$ 26,070	$ 109,839	$ 140,959	$ 136,515
Annual Prospective Limitation	524
Annual Deemed Worthless	3,487
1998 - 2004 [Member]
Summary Of Tax Credit Carry Forward And Operating Loss Carry Forwards [Line Items]
Total	8,207
Annual Prospective Limitation	524
Annual Deemed Worthless	3,487
2005 - 2013 [Member]
Summary Of Tax Credit Carry Forward And Operating Loss Carry Forwards [Line Items]
Total	$ 17,863