Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2017

Supplemental Cash Flow Elements [Abstract]

Supplemental Cash Flow Information

Supplemental cash flows and non-cash transactions were as follows for the periods indicated (in thousands):

	Year Ended December 31,
	2017		2016		2015
Cash paid for interest	$	22	$	2	$	13
Cash paid for federal and state taxes	459		2,589		6,197
Non-cash transactions:
Change in accounts payable related to property and equipment     additions	70		679		1,707
Property and equipment acquired under capital leases	1,808		—		—