CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 45,228	$ 43,365
Adjustments to reconcile net income to net cash provided by operating activities:
(Gain)/Loss on disposal of assets	(5,570)	5
Reduction of seller notes and earnouts	(363)	(971)
Provision for doubtful accounts	8,545	6,580
Provision for deferred income taxes	(2,564)	(1,031)
Depreciation and amortization	28,019	25,432
Amortization of debt issuance costs	8,703	2,589
Compensation expense on stock options and restricted stock units	6,398	6,100
Changes in operating assets and liabilities, net of effects of acquired companies:
Accounts receivable	(14,586)	(10,266)
Inventories	(14,676)	(13,995)
Prepaid expenses, other current assets, and income taxes	5,028	(337)
Accounts payable	4,581	670
Accrued expenses and accrued interest payable	5,421	4,192
Accrued compensation related costs	(9,584)	(5,970)
Other	3,946	2,642
Net cash provided by operating activities	68,526	59,005
Cash flows from investing activities:
Purchase of property, plant and equipment (net of acquisitions)	(24,429)	(23,439)
Purchase of equipment leased to third parties under operating leases	(3,041)	(1,438)
Acquisitions (net of cash acquired)	(5,695)	(14,266)
Restricted cash	3,120	(3,120)
Proceeds from sale of property, plant and equipment	4,595
Net cash used in investing activities	(25,450)	(42,263)
Cash flows from financing activities:
Borrowings under term loan	225,000
Repayment of term loan	(294,706)
Borrowings under revolving credit agreement	163,000	(2,950)
Repayments under revolving credit agreement	(137,000)
Repayment of seller's notes and other contingent considerations	(9,168)	(3,416)
Repayment of capital lease obligations	(808)	(545)
Deferred financing costs	(3,665)
Excess tax benefit from stock-based compensation	2,214	685
Proceeds from issuance of common stock	1,628	2,206
Purchase and retirement of treasury stock	(1,566)
Net cash used in financing activities	(55,071)	(4,020)
Decrease in cash and cash equivalents	(11,995)	12,722
Cash and cash equivalents, at beginning of period	19,211	42,896
Cash and cash equivalents, at end of period	7,216	55,618
Cash paid during the period for:
Interest	16,299	16,902
Income taxes (net of refunds)	21,033	22,106
Non-cash financing and investing activities:
Issuance of restricted stock units	10,990	5,452
Issuance of notes in connections with acquisitions	$ 675	$ 7,625