Stock-Based Compensation, Non-Vested Stock Option Activity (Details) - Stock Options	3 Months Ended
	Mar. 31, 2021 $ / shares shares
Status of the Company's non-vested options and changes during the year
Non-vested options at the beginning of the period (in shares) | shares	36,989,300
Non-vested options, options granted (in shares) | shares	215,080
Non-vested options, options vested (in shares) | shares	(91,200)
Non-vested options, options forfeited (in shares) | shares	(31,160)
Non-vested options at the end of the period (in shares) | shares	37,082,020
Weighted Average Fair Value at Grant Date
Weighted average fair value at the grant date, options outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 6.43
Weighted average fair value at grant date, options granted (in dollars per share) | $ / shares	12.11
Weighted average fair value at grant date, options vested (in dollars per share) | $ / shares	3.88
Weighted average fair value at grant date, options forfeited (in dollars per share) | $ / shares	5.77
Weighted average fair value at the grant date, options outstanding at the end of the period (in dollars per share) | $ / shares	$ 6.46