CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 8,937	$ 3,979
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation and amortization	27,024	24,808
Provision for doubtful accounts	3,190	3,468
Amortization of debt discount and debt issuance costs	552	391
Stock-based compensation	1,095	1,078
Deferred income taxes	41	59
Equity in earnings of an unconsolidated affiliate	(1,402)	(516)
Changes in operating assets and liabilities, excluding the effects of acquisitions:
Accounts receivable	(2,390)	4,412
Materials and supplies, prepayments, and other current assets	(5,184)	7,810
Accounts payable and accrued liabilities, advance payments and deposits and other current liabilities	(11,313)	(21,115)
Accrued taxes	4,507	(1,138)
Other	(4,029)	(2,242)
Net cash provided by operating activities	21,028	20,994
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(19,055)	(16,270)
Decrease in restricted cash		467
Net cash used in investing activities	(19,055)	(15,803)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from borrowings under revolver loan	27,925	11,000
Principal repayments of revolver loan	(15,079)
Proceeds from stock option exercises	103
Principal repayments of term loan	(6,267)	(3,048)
Dividends paid on common stock	(3,553)	(3,384)
Distributions to non-controlling interests	(424)	(462)
Investments made by non-controlling interests	450	507
Purchase of common stock	(170)	(91)
Net cash (used in) provided by financing activities	2,985	4,522
NET CHANGE IN CASH AND CASH EQUIVALENTS	4,958	9,713
CASH AND CASH EQUIVALENTS, beginning of the period	48,735	37,330
CASH AND CASH EQUIVALENTS, end of the period	$ 53,693	$ 47,043