Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	11 Months Ended
	Oct. 31, 2018	Oct. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Statutory tax rate		21.00%	35.00%
Increase in deferred tax assets corresponding decrease to income tax expense	$ 83,000	$ 83,000
Decrease in long term tax liability corresponding decrease to income tax expense	170,000	170,000
Decrease in income tax expense	252,000	252,000
Unrecognized tax benefits	$ 36,200	$ 36,200
U.S. federal tax authorities [Member] | Earliest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2013
U.S. federal tax authorities [Member] | Latest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2017
U.S. state tax authorities [Member] | Earliest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2008
U.S. state tax authorities [Member] | Latest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2017
Foreign tax authorities [Member] | Earliest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2012
Foreign tax authorities [Member] | Latest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2017