Quarterly Data (Unaudited) - Additional Information (Details)	3 Months Ended			12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares	Mar. 31, 2018 USD ($) $ / shares	Dec. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) $ / shares	Dec. 31, 2017 USD ($)
Quarterly Data (Unaudited)
Net income adjustment due to the resolution of litigation		$ 710,000,000
Impact on diluted earnings per share related to litigation settlement action | $ / shares		1.16
Net income adjustment for measurement period from accounting pursuant to Tax Cuts and Jobs Act of 2017		$ 217,000,000	$ 762,000,000
Impact on diluted earnings per share as a result of the Tax Cuts And Jobs Act Of 2017		0.36	1.25		1.24
Net income adjustment due to the Company’s ongoing IRS examination under the Compliance Assurance Process (CAP) and new guidance released under the Tax Cuts and Jobs Act	$ 60,000,000
Impact on diluted earnings per share due to the Company’s ongoing IRS examination under the Compliance Assurance Process (CAP) and new guidance released under the Tax Cuts and Jobs Act | $ / shares	0.11
Net income adjustment due to completing the Tax Cuts and Jobs Act of 2017 accounting	$ 41,000,000
Impact on diluted earnings per share due to completing the Tax Cuts and Jobs Act of 2017 accounting | $ / shares	0.07
Aggregate net income adjustments due the quarterly adjustments				$ 946,000,000
Impact on diluted earnings per share in aggregate of quarterly adjustments | $ / shares				1.57