Note 2 - Significant Accounting Policies (Details Textual) - USD ($)					3 Months Ended								4 Months Ended	12 Months Ended
	Feb. 21, 2020	Oct. 17, 2019	Oct. 11, 2019	Apr. 17, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	May 21, 2020	Dec. 31, 2019	Dec. 31, 2018
Investment Income, Nonoperating, Total					$ 1,532,912	$ 2,178,777	$ 2,592,502	$ 2,434,969	$ 2,331,871	$ 1,961,856	$ 1,484,040	$ 0		$ 8,739,160	$ 5,777,767
Administrative Expenses														120,000	86,000
Franchise Taxes														200,100	144,845
Income Tax Expense (Benefit), Total					321,986	$ 370,572	$ 536,681	$ 500,833	504,446	$ 394,468	$ 284,000	$ 0		1,730,072	1,182,914
Cash Equivalents, at Carrying Value, Total					0				0					0	0
Stock Redeemed During Period, Value Amount Invested in Government Securities														35,940,000
Investment in Trust Account, Deposits														3,742,794
Price Per Share of Common Stock Issued in IPO Not redeemed in Connection With Stockholder Vote to Approve Extension for Each Month		$ 0.033
Assets Held-in-trust, Noncurrent					391,964,540				$ 418,727,517					391,964,540	418,727,517
Investment Income Held in Trust Account														8,739,160	5,777,767
Franchise Taxes Paid														260,630
Payments for Administrative Services, Related Party														120,000	$ 80,000
Stock Redeemed or Called During Period, Value														36,823,301
Maximum Redemption Threshold That Would Cause Net Tangible Assets					$ 5,000,001									$ 5,000,001
Temporary Equity, Shares Outstanding					37,725,710				41,400,000					37,725,710	41,400,000
Temporary Equity, Redemption Price Per Share					$ 10.10				$ 10					$ 10.10	$ 10
Offering Costs				$ 9,506,582
Payments of Stock Issuance Costs				8,280,000											$ 8,280,000
Professional, Printing, Filing, Regulatory, And Other Costs				1,226,582
Unrecognized Tax Benefits, Ending Balance					$ 0				$ 0					0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total					0				0					0	0
Trust Account [Member]
Payments for Administrative Services, Related Party														120,000
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Income Taxes Paid														1,826,000	970,000
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Trust Account [Member]
Income Taxes Paid														2,041,000
State and Local Jurisdiction [Member]
Franchise Taxes														200,100	144,845
Franchise Taxes Paid														260,730	0
Taxes Payable, Total					$ 84,214				$ 144,845					84,214	144,845
State and Local Jurisdiction [Member] | Trust Account [Member]
Franchise Taxes Paid														260,630
Subsequent Event [Member]
Price Per Share of Common Stock Issued in IPO Not redeemed in Connection With Stockholder Vote to Approve Extension for Each Month													$ 0.033
US Treasury Securities [Member]
Investment in Trust Account				$ 414,000,000										$ 378,060,000	$ 414,000,000
Common Class A [Member]
Weighted Average Number of Shares Outstanding, Basic and Diluted														40,582,734	41,400,000
Stock Redeemed or Called During Period, Shares			3,594,000											3,594,000
Stock Redeemed or Called During Period, Value			$ 36,823,301
Stock Issued During Period, Shares, New Issues														37,806,000
Temporary Equity, Shares Outstanding					37,806,000				41,400,000					37,806,000	41,400,000
Temporary Equity, Redemption Price Per Share					$ 10.10				$ 10					$ 10.10	$ 10
Common Class A [Member] | Subsequent Event [Member]
Stock Redeemed or Called During Period, Shares	2,189,801
Price Per Share of Common Stock Issued in IPO Not redeemed in Connection With Stockholder Vote to Approve Extension for Each Month	$ 0.033
Stock Redeemed or Called During Period, Value	$ 22,811,431
IPO [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount														20,700,000
Private Placement [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount														10,280,000