Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Accounts receivable, allowance (in dollars)	$ 0	$ 0
Stockholders’ equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	245,000,000	245,000,000
Common stock, shares issued (in shares)	71,727,021	71,126,314
Common stock, shares outstanding (in shares)	45,107,805	44,507,098
Treasury stock, shares (in shares)	26,619,216	26,619,216