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	$ 8,636	$ 6,752
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Loss on disposal of assets		5
Reduction of seller notes and earnouts	(177)	(257)
Provision for bad debts	4,723	4,078
Provision for deferred income taxes		(343)
Depreciation and amortization	8,285	7,292
Amortization of debt issuance costs	863	748
Compensation expense on restricted stock	1,971	1,658
Excess tax benefit from stock-based compensation	(209)	(816)
Changes in operating assets and liabilities, net of effects of acquired companies:
Accounts receivable	851	5,483
Inventories	(7,868)	(2,277)
Prepaid expenses, other current assets, and income taxes	(2,234)	(3,010)
Accounts payable	(522)	(6,339)
Accrued expenses and accrued interest payable	4,294	2,040
Accrued compensation related costs	(17,504)	(25,531)
Other	183	(1,794)
Net cash provided by (used in) operating activities	1,292	(12,311)
Cash flows from investing activities:
Purchase of property, plant and equipment (net of acquisitions)	(4,777)	(5,437)
Purchase of equipment leased to third parties under operating leases	(539)
Acquisitions and contingent purchase price (net of cash acquired)	(2,402)	(4,941)
Proceeds from sale of property, plant and equipment		3
Restricted cash	(3,120)
Net cash used in investing activities	(10,838)	(10,375)
Cash flows from financing activities:
Borrowings under revolving credit agreement		10,000
Repayment of term loan	(1,450)	(750)
Scheduled repayment of seller's notes	(488)	(406)
Deferred financing costs		(4,189)
Excess tax benefit from stock-based compensation	209	816
Proceeds from issuance of common stock	627	573
Net cash (used in) provided by financing activities	(1,102)	6,044
Decrease in cash and cash equivalents	(10,648)	(16,642)
Cash and cash equivalents, at beginning of period	42,896	36,308
Cash and cash equivalents, at end of period	$ 32,248	$ 19,666