Recent Accounting Changes and Accounting Pronouncements Accounting Standard Update 2016-01 (Details) - Accounting Standards Update 2016-01 [Member] $ in Millions	3 Months Ended
	Jun. 30, 2018 USD ($)
Other Comprehensive Income (Loss) [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 11.0
Deferred Tax Asset [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 2.6