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Preferred and Common Stock - Additional Information (Details) |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |  |  |  |  |  |  |  |
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Oct. 02, 2017 $ / shares shares | Jul. 30, 2015 Tranche | Sep. 30, 2014 USD ($) $ / shares shares | Dec. 31, 2019 USD ($) $ / shares shares | Sep. 30, 2019 $ / shares | Jun. 30, 2019 $ / shares | Mar. 31, 2019 $ / shares | Dec. 31, 2018 USD ($) $ / shares shares | Sep. 30, 2018 $ / shares | Jun. 30, 2018 $ / shares | Mar. 31, 2018 $ / shares | Dec. 31, 2017 USD ($) $ / shares | Sep. 30, 2017 $ / shares | Jun. 30, 2017 $ / shares shares | Mar. 31, 2017 $ / shares | Dec. 31, 2021 USD ($) | Dec. 31, 2019 USD ($) class_of_stock $ / shares shares | Dec. 31, 2018 USD ($) $ / shares shares | Dec. 31, 2017 USD ($) $ / shares shares | Dec. 31, 2016 $ / shares | Dec. 31, 2015 $ / shares | Nov. 14, 2019 USD ($) | Nov. 06, 2019 USD ($) | Oct. 15, 2019 USD ($) | Aug. 06, 2019 USD ($) | May 14, 2019 USD ($) | May 02, 2019 USD ($) | Feb. 19, 2019 USD ($) | Dec. 01, 2015 USD ($)
Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock, number of classes | class_of_stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock par value (usd per share) | $ / shares |  |  | $ 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public offering of preferred stock |  |  | $ 1,250,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Depository shares sold (in shares) | shares | 24,022 |  | 25,000,000 |  |  |  |  |  |  |  |  |  |  | 12,958,767 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from public offering |  |  | $ 1,213,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock conversion rate |  |  | 0.10 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Conversion of stock, shares converted (in shares) | shares | 31,420 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares authorized (in shares) | shares |  |  |  | 600,000,000 |  |  |  |  |  |  |  |  |  |  |  |  | 600,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Common stock outstanding (in shares) | shares |  |  |  | 432,855,183 |  |  |  |  |  |  |  |  |  |  |  |  | 432,855,183 |  |  |  |  |  |  |  |  |  |  |  |
Common stock, dividends declared per share (usd per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.12 | $ 0.24 | $ 0.24 |  |  |  |  |  |  |  |  |  |
Dividends paid per share (usd per share) | $ / shares |  |  |  | $ 0.02 | $ 0.02 | $ 0.02 | $ 0.06 | $ 0.06 | $ 0.06 | $ 0.06 | $ 0.06 | $ 0.06 | $ 0.06 | $ 0.06 | $ 0.06 |  |  | $ 0.24 | $ 0.24 |  |  |  |  |  |  |  |  |  |
Number of shares available for issuance | shares |  |  |  | 47,000,000 |  |  |  |  |  |  |  |  |  |  |  |  | 47,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Common stock reserved for future issuance (in shares) | shares |  |  |  | 37,000,000 |  |  |  |  |  |  |  |  |  |  |  |  | 37,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Stock-based Compensation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock based compensation expense (benefit), before tax |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 78,000,000 | $ 50,000,000 | $ 54,000,000 |  |  |  |  |  |  |  |  |  |
Stock based compensation expense, after tax |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 70,000,000 | $ 39,000,000 | $ 36,000,000 |  |  |  |  |  |  |  |  |  |
Share-based payment arrangement included in cash bonus award |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 21,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Stock based compensation expense, stock awards percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 85.00% | 85.00% |  |  |  |  |  |  |  |  |  |
Stock-based compensation expense capitalized |  |  |  | $ 0 |  |  |  | $ 0 |  |  |  | $ 0 |  |  |  |  | 0 | $ 0 | $ 0 |  |  |  |  |  |  |  |  |  |
Unrecognized compensation costs on non-vested stock option grants (pretax) |  |  |  | 50,000,000 |  |  |  |  |  |  |  |  |  |  |  |  | $ 50,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Unrecognized compensation costs on non-vested awards, weighted average period of recognition in years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 year 3 months 18 days |  |  |  |  |  |  |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value (in usd per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 11.93 | $ 9.79 | $ 6.26 |  |  |  |  |  |  |  |  |  |
Average risk-free interest rate. percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.60% |  |  |  |  |  |  |  |  |  |  |  |
Number of options, outstanding weighted average remaining contractual life |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 years 4 months 24 days |  |  |  |  |  |  |  |  |  |  |  |
Total intrinsic value of options outstanding |  |  |  | $ 40,000,000 |  |  |  |  |  |  |  |  |  |  |  |  | $ 40,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Stock options vested (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,900,000 |  |  |  |  |  |  |  |  |  |  |  |
Weighted average remaining contractual life, vested and exercisable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 years |  |  |  |  |  |  |  |  |  |  |  |
Weighted average exercise price, vested and exercisable (in usd per share) | $ / shares |  |  |  | $ 25.80 |  |  |  |  |  |  |  |  |  |  |  |  | $ 25.80 |  |  |  |  |  |  |  |  |  |  |  |
Total intrinsic value of options vested and exercisable |  |  |  | $ 36,000,000 |  |  |  |  |  |  |  |  |  |  |  |  | $ 36,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from exercise of employee stock options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 56,000,000 | $ 16,000,000 | $ 50,000,000 |  |  |  |  |  |  |  |  |  |
Total tax benefit realized from these exercises |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,000,000 | 2,000,000 | 4,000,000 |  |  |  |  |  |  |  |  |  |
Total intrinsic value of options exercised |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 17,000,000 | $ 7,000,000 | 13,000,000 |  |  |  |  |  |  |  |  |  |
Restructuring and Other Charges |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock-based Compensation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock based compensation expense (benefit), before tax |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ (3,000,000) |  | $ (13,000,000) |  |  |  |  |  |  |  |  |  |
Stock Options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock-based Compensation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock options granted, vesting period |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 years |  |  |  |  |  |  |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, expiration period |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10 years |  |  |  |  |  |  |  |  |  |  |  |
Stock options granted, contractual term |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6 months |  |  |  |  |  |  |  |  |  |  |  |
Average risk-free interest rate. percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.50% |  |  |  |  |  |  |  |  |  |  |  |
Volatility, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 34.00% | 38.10% |  |  |  |  |  |  |  |  |  |
Dividend yield, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.90% |  |  |  |  |  |  |  |  |  |  |  |
Annual pre- and post-vesting forfeitures, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.00% |  |  |  |  |  |  |  |  |  |  |  |
Exercise behavior, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 61.00% |  |  |  |  |  |  |  |  |  |  |  |
Life (years) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6 years |  |  |  |  |  |  |  |  |  |  |  |
Restricted Stock Units (RSUs) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock-based Compensation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock options granted, contractual term |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 years |  |  |  |  |  |  |  |  |  |  |  |
Percentage of remaining share based compensation expenses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 95.00% |  |  |  |  |  |  |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value (in usd per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 20.25 | $ 0.027 |  |  |  |  |  |  |  |  |  |  |
Volatility, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 33.40% | 32.00% |  |  |  |  |  |  |  |  |  |  |
Common stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Conversion of stock, shares converted (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 39,242,706 |  |  |  |  |  |  |  |  |  |
Class B Mandatory Convertible Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage ownership |  |  | 5.375% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mandatory convertible preferred stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Depository shares sold (in shares) | shares | 24,975,978 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock liquidation preference (usd per share) | $ / shares |  |  | $ 500 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred shares (in shares) | shares |  |  | 2,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock conversion rate | 0.1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock conversion price (in usd per share) | $ / shares | $ 1.56996 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Conversion of stock, shares converted (in shares) | shares | 39,211,286 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Class A |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares of preferred stock authorized (in shares) | shares |  |  |  | 660,000 |  |  |  |  |  |  |  |  |  |  |  |  | 660,000 |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock par value (usd per share) | $ / shares |  |  |  | $ 100 |  |  |  |  |  |  |  |  |  |  |  |  | $ 100 |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock dividend declared (usd per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 3.75 | $ 3.75 | $ 3.75 |  |  |  |  |  |  |  |  |  |
Preferred stock, shares outstanding | shares |  |  |  | 546,024 |  |  |  | 546,024 |  |  |  |  |  |  |  |  | 546,024 | 546,024 |  |  |  |  |  |  |  |  |  |  |
Preferred Class B |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares of preferred stock authorized (in shares) | shares |  |  |  | 10,000,000 |  |  |  |  |  |  |  |  |  |  |  |  | 10,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock par value (usd per share) | $ / shares |  |  |  | $ 1 |  |  |  |  |  |  |  |  |  |  |  |  | $ 1 |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock dividend declared (usd per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 | $ 0 | $ 20.1563 | $ 26.8750 | $ 26.8750 |  |  |  |  |  |  |  |
Preferred stock, shares outstanding | shares |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |
Cash paid for dividends, preferred stock (per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 20.1563 |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Award, Tranche One | Stock Options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock-based Compensation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting rights, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 33.33% |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Award, Tranche Two | Stock Options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock-based Compensation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting rights, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 33.33% |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Award, Tranche Three | Stock Options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock-based Compensation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting rights, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 33.33% |  |  |  |  |  |  |  |  |  |  |  |
Convertible Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of repayment tranches | Tranche |  | 2 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Convertible Debt | Tranche Due December 2015 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 115,000,000
Convertible Debt | Tranche Due October 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 403,000,000 |  |  |  |  |
February 2019 ASR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share Activity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock repurchase program, authorized amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 700,000,000 |
May 2019 ASR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share Activity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock repurchase program, authorized amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 200,000,000 | $ 500,000,000 | $ 200,000,000 |  |
Share Repurchases Program November 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share Activity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock repurchase program, authorized amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 50,000,000 |  |  |  |  |  |  |
Accelerated Share Repurchase Program |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share Activity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock repurchase program, remaining repurchase amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 350,000,000 |  |  |  |  |  |
Scenario, Forecast |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock-based Compensation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash payments for performance awards |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 23,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |

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