Fair Value Measurement - Schedule of Assets Measured at Fair Value on Recurring Basis (Details) - Recurring [Member]	Sep. 30, 2018 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments and cash held in Trust Account	$ 400,382,026
Total	400,382,026
Quoted Prices in Active Markets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments and cash held in Trust Account	400,382,026
Total	$ 400,382,026