Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
CPA®:18 – Global stockholders’ equity:
Preferred stock, par value (usd per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (shares)	50,000,000	50,000,000
Preferred stock, shares issued (shares)	0	0
Class A
CPA®:18 – Global stockholders’ equity:
Common stock, par value (usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (shares)	320,000,000	320,000,000
Common stock, shares outstanding (shares)	115,444,107	114,589,333
Class C
CPA®:18 – Global stockholders’ equity:
Common stock, par value (usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (shares)	80,000,000	80,000,000
Common stock, shares outstanding (shares)	31,840,141	31,641,265