CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 11,296	$ 5,735
Adjustments to reconcile net income to cash (used in) provided by operating activities:
Depreciation and amortization	8,195	8,807
Amortization of discount and deferred debt issuance costs	870	675
Share-based compensation	704	1,174
Deferred income taxes, net	1,964	1,100
Provision for losses on accounts receivable	1,818	1,549
Loss on sale of assets	102	35
Changes in operating assets and liabilities	(15,779)	(20,122)
Cash provided by (used in) operating activities	9,170	(1,047)
Cash flows from investing activities:
Purchases of property and equipment	(4,103)	(4,261)
Acquisitions of businesses, net of cash acquired	(7)	(4,550)
Proceeds from sale of assets	81	10
Cash used in investing activities	(4,029)	(8,801)
Cash flows from financing activities:
Long-term debt repayments	(6,904)	(1,188)
Long-term debt borrowings		71
Payments on obligations under capital lease	(1,594)	(1,497)
Debt issuance costs	(8)
Cash used in financing activities	(8,506)	(2,614)
Effect of exchange rate changes on cash and cash equivalents	(66)	64
Decrease in cash and cash equivalents	(3,431)	(12,398)
Cash and cash equivalents at beginning of period	50,134	25,651
Cash and cash equivalents at end of period	46,703	13,253
Supplemental schedule of non-cash investing and financing activities:
Capital lease obligations	$ 476	$ 1,298