Description of the Business and Summary of Significant Accounting Policies - Other Information (Details) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018 shares	Sep. 30, 2017 shares	Sep. 30, 2018 Segment shares	Sep. 30, 2017 shares	Mar. 31, 2019 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of business segments | Segment			4
Stock Options
Business Acquisition [Line Items]
Anti-dilutive securities (in shares) | shares	2.6		2.6	2.6
Restricted Stock Units
Business Acquisition [Line Items]
Anti-dilutive securities (in shares) | shares	2.9	4.2	2.9	4.2
Minimum | Accounting Standards Update 2016-02 | Scenario, Forecast
Business Acquisition [Line Items]
Addition of assets/liabilities to balance sheet, due to adoption of accounting principle | $					$ 175.0
Maximum | Accounting Standards Update 2016-02 | Scenario, Forecast
Business Acquisition [Line Items]
Addition of assets/liabilities to balance sheet, due to adoption of accounting principle | $					$ 225.0