Income Taxes (Reconciliation of the Difference Between the Companys Effective Tax Rate and the U.S. Federal Statutory Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2019	Dec. 31, 2018	Oct. 31, 2018	Dec. 31, 2017	Oct. 31, 2017
Reconconciliation to the Company's effective income tax rate
Statutory U.S. federal income tax rate (as a percent)	21.00%	21.00%	23.30%	35.00%	35.00%
State income tax, net of federal income tax benefits	4.70%		4.40%		3.50%
Net income attributable to non-controlling and other beneficial interests	(1.20%)		(0.70%)		(1.80%)
Non-recurring impact of U.S. tax reform	0.00%		4.40%		0.00%
Stock-based compensation	0.20%		0.40%		0.30%
Net excess tax benefits from stock-based compensation plans	(1.00%)		(3.20%)		0.00%
Other items	0.50%		0.20%		0.00%
Effective income tax rate	24.20%		28.80%		37.00%
Net excess tax benefit attributable to the exercise of employee stock options and vesting of restricted stock awards	$ 5.4		$ 17.5		$ 3.2