Note 2 - Significant Accounting Policies (Details Textual) - USD ($)		12 Months Ended
	Apr. 17, 2018	Dec. 31, 2018	Dec. 31, 2017
Cash Equivalents, at Carrying Value, Total		$ 0	$ 0
Assets Held-in-trust, Noncurrent		418,727,517
Investment Income Held in Trust Account		5,777,767
Income Taxes Paid		970,000
Payments for Administrative Services, Related Party		80,000
Maximum Redemption Threshold That Would Cause Net Tangible Assets		5,000,001
Payments of Stock Issuance Costs		9,506,582
Payments for Underwriting Expense		8,280,000
Professional, Printing, Filing, Regulatory, And Other Costs		1,226,582
Unrecognized Tax Benefits, Ending Balance		0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total		$ 0	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	35.00%
State and Local Jurisdiction [Member]
Taxes Payable, Total		$ 144,845
Common Class A [Member]
Stock Issued During Period, Shares, New Issues		41,400,000
Temporary Equity, Redemption Price Per Share		$ 10	$ 0
US Treasury Securities [Member]
Investment in Trust Account		$ 414,000,000
IPO [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		20,700,000
Stock Issued During Period, Shares, New Issues	41,400,000
Private Placement [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		10,280,000