Annual report pursuant to Section 13 and 15(d)

Summarized Quarterly Financial Data (unaudited) (Details)

v3.8.0.1
Summarized Quarterly Financial Data (unaudited) (Details) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]                      
Revenues $ 1,746 $ 1,403 $ 1,241 $ 1,211 $ 572 $ 465 $ 177 $ 69 $ 5,601 $ 1,283 $ 271
Income (loss) from operations 441 297 274 376 122 15 (76) (91) 1,388 (30) (449)
Net income (loss) 280 90 21 172 150 (131) (335) (349) 563 (665) (1,097)
Net income (loss) attributable to common stockholders $ 127 $ (289) $ (285) $ 54 $ 110 $ (101) $ (298) $ (321) $ (393) $ (610) $ (975)
Net income (loss) per share attributable to common stockholders—basic and diluted $ 0.54 [1] $ (1.24) [1] $ (1.23) [1] $ 0.23 [1] $ 0.48 [1] $ (0.44) [1] $ (1.31) [1] $ (1.41) [1] $ (1.68) [2] $ (2.67) [2] $ (4.30) [2]
[1] The sum of the quarterly net income (loss) per share—basic and diluted may not equal the full year amount as the computations of the weighted average common shares outstanding for basic and diluted shares outstanding for each quarter and the full year are performed independently.
[2] Earnings per share in the table may not recalculate exactly due to rounding because it is calculated based on whole numbers, not the rounded numbers presented.