3. Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Allowance For Doubtful Accounts Details
Balance, beginning of year	$ 49	$ 49
Provision for doubtful accounts	17	0
Uncollectible accounts written off	(16)	0
Balance, end of year	$ 50	$ 49