Stock-Based Compensation - Summary of Stock Option Activity (Detail) - Stock Options [Member]	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Summary Of Stock Option Activities [Line Items]
Options Outstanding, Beginning balance, Shares | shares	1,220,442,000
Options Outstanding, Expired or cancelled | shares	(140,105,000)
Options Outstanding, Forfeited | shares	(41,436,000)
Options Outstanding, Ending balance, Shares | shares	1,038,901,000
Options Exercisable, Ending balance, Shares | shares	809,258,000
Options Outstanding, Beginning balance, Weighted Average Exercise Price | $ / shares	$ 7.72
Weighted Average Exercise Price, Expired or Cancelled | $ / shares	8.51
Weighted Average Exercise Price, Forfeited | $ / shares	7.09
Options Outstanding, Ending balance, Weighted Average Exercise Price | $ / shares	7.64
Options Outstanding, Exercisable at End of Year, Weighted Average Exercise Price | $ / shares	$ 7.72