Stock Options (Detail)	6 Months Ended
	Jun. 30, 2020 $ / shares shares
Shares
Nonvested shares, Beginning balance | shares	439,194
Granted, shares | shares	606,900
Vested/Issued, shares | shares	(101,661)
Nonvested shares, Ending balance | shares	944,433
Weighted Average Grant-Date Fair Value
Nonvested, Beginning balance, Weighted Average Grant-Date Fair Value | $ / shares	$ 19.38
Granted, Weighted Average Grant-Date Fair Value | $ / shares	7.86
Vested/Issued, Weighted Average Grant-Date Fair Value | $ / shares	32.46
Nonvested, Ending balance, Weighted Average Grant-Date Fair Value | $ / shares	$ 10.57