Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2019	Dec. 31, 2018	Oct. 31, 2018	Dec. 31, 2017	Oct. 31, 2017
Income Taxes [Abstract]
Maximum Federal statutory rate (as a percent)	21.00%	21.00%	23.30%	35.00%	35.00%
Total non-recurring charge to Income Taxes to reflect the estimated impact of the enactment of the Tax Cuts and Jobs Act			$ 24,000
Non-recurring charge to income taxes to reflect the revaluation of the Company's deferred tax assets and liabilities to reflect the impact of the enactment of the Tax Cuts and Jobs Act			21,200
Non-recurring charge to income taxes to reflect the deemed repatriation of foreign-source net earnings to reflect the impact of the enactment of the Tax Cuts and Jobs Act			2,800
Income tax expense on net income attributable to redeemable non-controlling and other beneficial interests not taxable by the Company	$ 8,400		4,400
Income tax provision principally related to limitations on the deductibility of executive compensation related to 2017 Tax Act taking effect in current period	3,200
Net excess tax benefit attributable to the exercise of employee stock options and vesting of restricted stock awards	5,400		17,500		$ 3,200
Deferred tax assets, valuation allowance	0		0
Income Taxes [Line Items]
Interest and penalties recognized in the income tax provision due to the Company's tax position	$ 100		100		0
Income Tax Examination Description	The Company is generally no longer subject to income tax examinations by U.S. federal, state, local or non-U.S. taxing authorities for fiscal years prior to fiscal 2015.
Non-current tax benefits that would change the effective tax rate if recognized	$ 700		700		$ 1,000
Current unrecognized tax benefits	700
Accrued interest and penalties	800		$ 700
Canadian Affliate [Member]
Income Taxes [Line Items]
Undistributed earnings of certain foreign subsidiaries	8,500
Dividends received	65,200
Tax expense reduction due to a realized foreign exchange loss	500
United Kingdom [Member]
Income Taxes [Line Items]
Undistributed earnings of certain foreign subsidiaries	$ 11,400