CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
CONSOLIDATED BALANCE SHEETS
Allowance for doubtful accounts	$ 262	$ 132
Accumulated amortization	$ 169,329	$ 127,172
Preferred share, par value	$ 0.01	$ 0.01
Preferred share, shares authorized	50,000,000	0
Preferred share, shares issued	0	0
Preferred share, shares outstanding	0	0
Common share, par value	$ 0.01	$ 0.01
Common share, shares authorized	600,000,000	600,000,000
Common share, shares outstanding	159,658,948	152,979,479
Treasury stock	1,100	0