| Label | Element | Value |
|---|---|---|
| Common Stock [Member] | ||
| Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1 | $ 242,600,000 |
| Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1 | 212,000,000.0 |
| Additional Paid-in Capital [Member] | ||
| Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1 | 1,166,900,000 |
| Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1 | 1,167,800,000 |
| Treasury Stock [Member] | ||
| Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1 | (2,499,300,000) |
| Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1 | (252,100,000) |
| Retained Earnings [Member] | ||
| Cumulative Effect of New Accounting Principle in Period of Adoption | us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption | 10,400,000 |
| Cumulative Effect of New Accounting Principle in Period of Adoption | us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption | 9,300,000 |
| Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1 | 1,972,500,000 |
| Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1 | $ 3,915,600,000 |