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	$ 5,883		$ 6,188
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for (benefit of) deferred income taxes	(3,543)		628
Depreciation and amortization	5,992		5,391
Non-cash interest on convertible notes	467		960
Provision for bad debts	601		331
Stock-based compensation	2,221		1,176
Loss on the disposition of property and equipment	63		9
Loss on conversion of convertible debt	5,715
Changes in operating accounts:
Accounts receivable	(8,785)		(1,255)
Inventories	(3,320)		(4,097)
Prepaid expenses and other current assets	(440)		239
Accounts payable	(755)		2,305
Accrued liabilities	5,418		4,309
Customer deposits	1,284		(330)
Deferred revenue	1,798		397
Other operating assets and liabilities	(1,853)		(424)
Net cash provided by operating activities	10,746		15,827
Cash flows from investing activities:
Purchases of property and equipment	(2,295)		(755)
Additions to license and patent costs	(177)		(231)
Proceeds from disposition of property and equipment	4
Cash paid for acquisitions, net of cash assumed	(52,949)		(134,918)
Net cash used in investing activities	(55,417)		(135,904)
Cash flows from financing activities:
Proceeds from exercise of stock options and restricted stock, net	302		782
Cash disbursed in lieu of fractional shares related to stock split	(177)
Repayment of capital lease obligations	(38)		(36)
Net cash provided by financing activities	87		746
Effect of exchange rate changes on cash	(732)		238
Net decrease in cash and cash equivalents	(45,316)		(119,093)
Cash and cash equivalents at the beginning of the period	155,859		179,120
Cash and cash equivalents at the end of the period	110,543		60,027
Supplemental Cash Flow Information:
Interest payments	133		135
Income tax payments	739		168
Non-cash items:
Transfer of equipment from inventory to property and equipment, net	915	[1]	755	[1]
Transfer of equipment to inventory from property and equipment, net			773	[2]
Stock issued for conversions of 5.50% senior convertible notes	2,979
Notes redeemed for shares of common stock	42,060
Amount of notes converted	$ 42,060

[1] Inventory is transferred from inventory to property and equipment at cost when the Company requires additional machines for training or demonstration or for placement into on-demand parts locations

[2] In general, an asset is transferred from property and equipment, net into inventory at its net book value when the Company has identified a potential sale for a used machine.