Common Stock (Shelf Registration Narrative) (Detail) - Shelf Registration - USD ($) shares in Millions, $ in Millions	1 Months Ended
	Mar. 31, 2017	Jun. 30, 2020
Components of common Stock [Line Items]
Common stock and warrants	$ 100.0
Common stock to be sold by directors and management in future public offerings	5.0
Remaining common stocks and warrants under shelf registration		$ 95.6