Credit Facility - Interest Rate Swaps (Details) - USD ($)	Jan. 31, 2018	Nov. 13, 2017	Nov. 01, 2017	Oct. 31, 2017	May 11, 2016
Line of Credit Facility [Line Items]
Net gains from cash flow hedges recorded in accumulated other comprehensive loss, net of tax	$ 15,700,000			$ 1,700,000
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net	5,000,000
Accumulated Net Gain (Loss) from Cash Flow Hedges
Line of Credit Facility [Line Items]
Tax related to amounts in accumulated other comprehensive loss	$ 5,800,000			$ 1,200,000
Interest Rate Swap
Line of Credit Facility [Line Items]
Notional amount		$ 285,000,000.0	$ 215,000,000.0		$ 105,000,000.0
Derivative, fixed interest rate (percent)		1.69%	1.65%		1.05%