Acquisitions and Divestments - Schedule of Pro Forma Financial Information Presents Combined Consolidated Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Business Combinations [Abstract] | ||
| Revenue | $ 9,850 | $ 9,904 |
| Net income (loss) attributable to stockholders | $ (84) | $ (277) |
| Net income (loss) per common share attributable to stockholders: | ||
| - Basic | $ (0.25) | $ (0.81) |
| - Diluted | $ (0.25) | $ (0.81) |