Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Operating activities:
Cash provided by operating activities	$ 15,865	$ 23,961
Investing activities:
Capital expenditures	(19,683)	(11,855)
Proceeds from sale of equipment	29	343
Proceeds from maturities of certificates of deposit	760	3,879
Proceeds from sale of equity method investments	8,000
Cash used in investing activities	(10,894)	(7,633)
Financing activities:
Payments on bank debt	(21,767)	(13,125)
Bank borrowings	14,000
Debt issuance cost	(608)
Proceeds from noncontrolling interests (Note 13)	4,000
Dividends	(2,471)	(2,409)
Cash used in financing activities	(6,846)	(15,534)
Increase (decrease) in cash, cash equivalents, and restricted cash	(1,875)	794
Cash, cash equivalents, and restricted cash, beginning of period	16,294	12,605
Cash, cash equivalents, and restricted cash, end of period	14,419	13,399
Cash and cash equivalents			$ 10,185	$ 12,483	$ 10,079
Restricted cash			4,234	3,811	3,320
Total cash, cash equivalents, and restricted cash	16,294	$ 12,605	$ 14,419	$ 16,294	$ 13,399
Liabilities assumed	$ 1,100