Income Taxes - Additional Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016 USD ($)	Jul. 31, 2015
Income Tax Examination [Line Items]
Effective Income Tax Rate Reconciliation, Percent	34.50%	34.20%	32.10%	34.40%
Unrecognized Tax Benefits, Period Increase (Decrease)			$ (7.0)
Income Tax Examination, Penalties and Interest Expense			(0.4)
Tax Adjustments, Settlements, and Unusual Provisions			$ (6.6)
Tax Settlement Impact			(2.3)
Minimum [Member] | State and Local Jurisdiction [Member]
Income Tax Examination [Line Items]
Income tax examination, tax years			2006
Minimum [Member] | Foreign Tax Authority [Member]
Income Tax Examination [Line Items]
Income tax examination, tax years			2006
Minimum [Member] | Internal Revenue Service (IRS) [Member]
Income Tax Examination [Line Items]
Income tax examination, tax years			2010
Minimum [Member] | New York City [Member]
Income Tax Examination [Line Items]
Income tax examination, tax years			2011
Minimum [Member] | New York State Division of Taxation and Finance [Member]
Income Tax Examination [Line Items]
Income tax examination, tax years			2012
Maximum [Member] | New York City [Member]
Income Tax Examination [Line Items]
Income tax examination, tax years			2013
Maximum [Member] | New York State Division of Taxation and Finance [Member]
Income Tax Examination [Line Items]
Income tax examination, tax years			2014