Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Cash flows from operating activities:
Net income	$ 11,946		$ 44,119		$ 38,941
Adjustments to reconcile net income to net cash provided by operating activities:
Benefit of deferred income taxes	(24,555)		(9,892)		(661)
Depreciation and amortization	55,188		30,444		21,229
Non-cash interest on convertible notes	224		974		3,876
Provision for bad debts	8,699		4,961		3,039
Stock-based compensation	32,793		13,558		5,118
Gain (loss) on the disposition of property and equipment	(227)		1,128		(674)
Deferred interest income			(1,018)
Loss on conversion of convertible debt	1,806		11,275		7,021
Changes in operating accounts:
Accounts receivable	(55,977)		(43,684)		(19,246)
Inventories	(30,754)		(30,893)		(12,225)
Prepaid expenses and other current assets	(9,235)		(1,780)		(794)
Accounts payable	23,482		7,620		(238)
Accrued liabilities	16,071		(6,495)		7,567
Customer deposits	1,921		1,904		(1,336)
Deferred revenue	8,686		7,526		1,164
Other operating assets and liabilities	11,043		(4,563)		(1,251)
Net cash provided by operating activities	51,111		25,184		51,530
Cash flows from investing activities:
Purchases of property and equipment	(22,727)		(6,972)		(3,224)
Additions to license and patent costs	(753)		(1,648)		(729)
Proceeds from disposition of property and equipment			1,882
Cash paid for acquisitions, net of cash assumed	(345,361)		(162,318)		(183,701)
Other investing activities	(6,600)		(4,701)
Net cash used in investing activities	(375,441)		(173,757)		(187,654)
Cash flows from financing activities:
Proceeds from issuance of common stock	299,729		272,076		106,889
Tax benefits from share-based payment arrangements	7,653		26,038		1,514
Proceeds from exercise of stock options and restricted stock, net	1,896		902		4,400
Cash disbursed in lieu of fractional shares related to stock split			(176)
Restricted cash			13
Repayment of capital lease obligations	(696)		(157)		(163)
Net cash provided by financing activities	308,582		298,696		112,640
Effect of exchange rate changes on cash	(5,706)		334		223
Net increase (decrease) in cash and cash equivalents	(21,454)		150,457		(23,261)
Cash and cash equivalents at the beginning of the period	306,316		155,859		179,120
Cash and cash equivalents at the end of the period	284,862		306,316		155,859
Supplemental Cash Flow Information:
Cash interest payments	888		1,584		9,113
Cash income tax payments	15,602		5,642		3,506
Transfer of equipment from inventory to property and equipment, net	5,891	[1]	4,886	[1]	4,057	[1]
Transfer of equipment to inventory from property and equipment, net	944	[2]	612	[2]	1,924	[2]
Stock issued for acquisitions of businesses	24,625		13,131		7,672
Notes redeemed for shares of common stock	$ 12,134		$ 80,754		$ 60,082

[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 Quickparts 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.