Common Stock (Common Stock Issued for Services) (Detail) - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Components of common Stock [Line Items]
Stock Issued During Period, Value, Issued for Services	$ 80,000	$ 60,000
Common Stock Issued for Services [Member] | Non Employee Directors
Components of common Stock [Line Items]
Stock Issued During Period, Shares, Issued for Services	136	136
Stock Issued During Period, Value, Issued for Services	$ 80,000	$ 60,000