Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Operating activities:
Cash provided by operating activities	$ 13,189	$ 14,894
Investing activities:
Capital expenditures	(10,428)	(5,144)
Proceeds from sale of equipment		325
Proceeds from maturities of certificates of deposit		1,935
Proceeds from sale of equity method investments	8,000
Cash used in investing activities	(2,428)	(2,884)
Financing activities:
Payments on bank debt	(16,255)	(6,563)
Bank borrowings	5,000
Proceeds from noncontrolling interests (Note 13)	4,000
Dividends	(1,236)	(1,206)
Cash used in financing activities	(8,491)	(7,769)
Increase in cash and cash equivalents	2,270	4,241
Cash, cash equivalents, and restricted cash, beginning of period	16,294	12,605
Cash, cash equivalents, and restricted cash, end of period	18,564	16,846
Cash and cash equivalents			$ 14,449	$ 12,483	$ 13,762
Restricted cash			4,115	3,811	3,084
Total cash, cash equivalents, and restricted cash	16,294	$ 12,605	$ 18,564	$ 16,294	$ 16,846
Liabilities assumed	$ 1,100