v3.8.0.1
Income Taxes - Consolidated Income Tax Expense (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]      
Federal $ 421 $ 485 $ 332
State and local 14 22 26
Total current provision 435 507 358
Deferred provision (109) 92 (19)
Income tax expense $ 326 $ 599 $ 339