Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	2 Months Ended	12 Months Ended
	Dec. 18, 2014	Feb. 01, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock Repurchased During Period, Value	$ 60	$ 100	$ 60
Common Stock, Shares Authorized			200,000,000	200,000,000
Common Stock, Par or Stated Value Per Share			$ 0.01	$ 0.01
Business Acquisition Stockholders Rights Plan Exercise Description			The rights would be exercisable only if a person or a group acquired or announced a tender or exchange offer to acquire 20% or more of our common stock or if we entered into other business combination transactions not approved by our board of directors.
Unclassified Preferred Stock
Preferred Stock, Shares Authorized			25,000,000
Series D Junior Participating Preferred Stock
Preferred Stock, Par or Stated Value Per Share			$ 120