Acquisitions 1 (Details) - USD ($) $ in Millions	3 Months Ended
	Jan. 31, 2018	Oct. 31, 2017	Jan. 31, 2017	Oct. 31, 2016
Atlanta Capital [Member]
Business Acquisition Contingent Consideration [Line Items]
Company's increase in profit interest percentage under acquisition agreement, during the period		0.45%
Non-controlling interest holders total (direct and indirect) profits interest, end of period	11.60%	11.60%
Profit interest granted to non-controlling interest holders under the Long-term Equity Incentive Plan			1.10%
Company's increase in indirect profit interest percentage under Long-term Equity Incentive Plan, during the period		1.10%		0.90%
Purchase of non-controlling interests	$ 2.5
Amount paid for indirect profit interest pursuant to the put and call provisions of the Long-term Equity Incentive Plan	$ 4.2		$ 1.9
Parametric Portfolio Associates [Member]
Business Acquisition Contingent Consideration [Line Items]
Company's increase in capital interest percentage under acquisition agreement, during the period	0.50%		0.50%
Company's increase in profit interest percentage under acquisition agreement, during the period	0.50%		0.50%
Non-controlling interest holders capital ownership percentage, end of period	0.80%	1.30%
Non-controlling interest holders total (direct and indirect) profits interest, end of period	5.50%	6.00%
Company's increase in indirect profit interest percentage under Long-term Equity Incentive Plan, during the period		0.50%
Purchase of non-controlling interests	$ 8.4		$ 6.9
Amount paid for indirect profit interest pursuant to the put and call provisions of the Long-term Equity Incentive Plan	$ 5.7