Mezzanine and Shareholders' Equity - Summary of Stock Option Activity Under Black-Scholes Option (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended				24 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Options exercised (in shares)	(241,214)	(488,464)
Weighted Average Remaining Contractual Term (Years)
Options outstanding (term)	5 years
Stock options
Shares
Beginning balance (in shares)	607,346	647,240	1,141,040	0	647,240	607,346	647,240	1,141,040	0
Options assumed in the Merger (see Note 3) (in shares)			1,141,040
Options granted (in shares)	279,698	155,000	0
Options exercised (in shares)	(241,214)	(639,800)	0
Options forfeited (in shares)	(78,378)	(9,000)	0
Ending balance (in shares)	607,346	647,240	1,141,040	0	647,240
Options exercisable (in shares)						439,776
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 5.62	$ 3.95	$ 0.00		$ 0.00
Options assumed in the Merger (see Note 3) (in dollars per share)			3.95
Options granted (in dollars per share)	17.24	9.85	0.00
Options exercised (in dollars per share)	6.09	4.11	0.00
Options forfeited (in dollars per share)	17.62	3.41	0.00
Ending balance (in dollars per share)	$ 9.22	$ 5.62	$ 3.95	$ 0.00	$ 5.62
Options exercisable (in dollars per share)						$ 4.58
Weighted Average Remaining Contractual Term (Years)
Options outstanding (term)	3 years 5 months 1 day	4 years 1 month 16 days	5 years 9 months 14 days	0 years
Options assumed in the Merger (see Note 3) (term)			5 years 10 months 6 days
Options exercisable (term)	2 years 1 month 2 days
Aggregate Intrinsic Value
Options outstanding							$ 9.2	$ 22.6	$ 0.0
Options assumed in the Merger (see Note 3)			$ 22.6
Options exercised	$ 2.7	$ 9.8
Options exercisable						$ 5.6
Board Members
Black-Scholes Option Pricing Model Assumptions:
Expected term	3 years
Annual dividend yield	0.00%
Forfeiture rate	0.00%
Executives
Weighted Average Exercise Price
Ending balance (in dollars per share)	$ 18.91
Black-Scholes Option Pricing Model Assumptions:
Expected term	3 years
Expected volatility rate	84.42%
Risk-free interest rate	1.65%
Market value of common stock						$ 18.91
Annual dividend yield	0.00%
Forfeiture rate	0.00%
Maximum | Board Members
Weighted Average Exercise Price
Ending balance (in dollars per share)	$ 18.11
Black-Scholes Option Pricing Model Assumptions:
Expected volatility rate	100.27%
Risk-free interest rate	2.51%
Market value of common stock						18.11
Minimum | Board Members
Weighted Average Exercise Price
Ending balance (in dollars per share)	$ 15.35
Black-Scholes Option Pricing Model Assumptions:
Expected volatility rate	90.50%
Risk-free interest rate	1.60%
Market value of common stock						$ 15.35
Allied Pacific of California
Shares
Beginning balance (in shares)	0	853,800	853,800	1,910,400	853,800	0	853,800	853,800	1,910,400
Options granted (in shares)	0	0	0
Options exercised (in shares)	0	0	(1,056,600)		(7,110,150)
Options forfeited (in shares)	(853,800)	0	0
Ending balance (in shares)	0	853,800	853,800	1,910,400	853,800
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 0.167	$ 0.167	$ 0.167		$ 0.167
Options granted (in dollars per share)	0.000	0.000	0.000
Options exercised (in dollars per share)	0.000	0.000	0.167
Options forfeited (in dollars per share)	0.167	0.000	0.000
Ending balance (in dollars per share)	$ 0.000	$ 0.167	$ 0.167	$ 0.167	$ 0.167
Weighted Average Remaining Contractual Term (Years)
Options outstanding (term)	0 years	9 months	1 year 9 months	2 years 9 months
Options exercisable (term)	0 years
Aggregate Intrinsic Value
Options outstanding						$ 0.0	$ 0.5	$ 0.5	$ 1.1
Options exercised			$ 0.6
Black-Scholes Option Pricing Model Assumptions:
Expected term		9 months
Allied Pacific of California | Maximum
Black-Scholes Option Pricing Model Assumptions:
Expected term			1 year 9 months
Expected volatility rate		41.60%	41.60%
Risk-free interest rate		1.86%	1.86%
Market value of common stock							$ 0.76	$ 0.76
Annual dividend yield		3.53%	3.53%
Forfeiture rate		6.80%	6.80%
Allied Pacific of California | Minimum
Black-Scholes Option Pricing Model Assumptions:
Expected term			11 months 5 days
Expected volatility rate		38.10%	38.10%
Risk-free interest rate		1.64%	1.64%
Market value of common stock							$ 0.52	$ 0.52
Annual dividend yield		2.23%	2.23%
Forfeiture rate		0.00%	0.00%