Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Feb. 28, 2018	Jan. 01, 2018	Nov. 30, 2017	Feb. 28, 2017
Federal Income Tax Note
Federal Statutory Income Tax Rate			35.00%
Unrecognized tax benefits, gross			$ 30.8	$ 30.0
Subsequent Event [Member]
Federal Income Tax Note
Federal Statutory Income Tax Rate		21.00%
Subsequent Event [Member] | Minimum
Federal Income Tax Note
Impact of Tax Legislation	$ 50.0
Subsequent Event [Member] | Maximum
Federal Income Tax Note
Impact of Tax Legislation	$ 65.0