Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash Flows from Operating Activities:
Net income (loss)	$ 6,028	$ (1,957)
Amounts to reconcile net income (loss) to net cash flows provided by operating activities:
Income from discontinued operations, net of taxes	(21)	(4)
Income from unconsolidated companies		(173)
Loss on disposals of long-lived assets		201
Provision (benefit) for deferred income taxes	4,479	(1,346)
Depreciation and amortization	32,434	29,057
Amortization of deferred financing costs	1,212	1,309
Amortization of discount on convertible notes	3,307	3,043
Stock-based compensation expense	2,356	2,323
Changes in:
Trade receivables	(21,036)	(32,134)
Interest receivable	551	5,089
Accounts payable and accrued liabilities	(18,728)	(11,478)
Other assets and liabilities	3,320	(1,882)
Net cash flows provided by (used in) operating activities - continuing operations	13,902	(7,952)
Net cash flows provided by (used in) operating activities - discontinued operations	13	(26)
Net cash flows provided by (used in) operating activities	13,915	(7,978)
Cash Flows from Investing Activities:
Purchases of property and equipment	(29,734)	(37,497)
Collection of notes receivable	2,870	2,465
Other investing activities	378	1,570
Net cash flows used in investing activities - continuing operations	(26,486)	(33,462)
Net cash flows used in investing activities - discontinued operations
Net cash flows used in investing activities	(26,486)	(33,462)
Cash Flows from Financing Activities:
Repayments under credit facility	(15,000)
Proceeds from exercise of stock option and purchase plans	3,232	4,052
Other financing activities, net	(187)	(42)
Net cash flows (used in) financing activities - continuing operations	(11,955)	4,010
Net cash flows provided by financing activities - discontinued operations
Net cash flows (used in) financing activities	(11,955)	4,010
Net change in cash and cash equivalents	(24,526)	(37,430)
Cash and cash equivalents - unrestricted, beginning of period	44,388	124,398
Cash and cash equivalents - unrestricted, end of period	$ 19,862	$ 86,968