Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Cash provided by operating activities - continuing operations	$ 6,571	$ 3,084
Cash used in operating activities - discontinued operations	(313)	(5,396)
Net cash provided by (used in) operating activities	6,258	(2,312)
Investing activities:
Purchases of investments		(552)
Proceeds from sale of investments	103	7,330
Proceeds from maturity of investments	80
Purchases of property, plant and equipment	(18)	(5)
Proceeds from sale of property, plant and equipment		378
Cash provided by investing activities - continuing operations	165	7,151
Cash provided by investing activities - discontinued operations	0	5,890
Net cash provided by investing activities	165	13,041
Financing activities:
Payment of withholding taxes on exercise of restricted stock units		(556)
Purchases of treasury stock	(12,945)	(690)
Cash used in financing activities - continuing operations	(12,945)	(1,246)
Cash used in financing activities - discontinued operations		(3,232)
Net cash used in financing activities	(12,945)	(4,478)
Increase (decrease) in cash and cash equivalents	(6,522)	6,251
Cash and cash equivalents, beginning of the period	37,128	60,980
Cash and cash equivalents, end of the period	30,606	67,231
Less cash and cash equivalents of discontinued operations at the end of the period	0	30,510
Cash and cash equivalents of continuing operations, end of the period	30,606	36,721
Non-cash investing and financing activities:
Issuance of common stock for vested restricted stock units	$ 263	$ 2,571