Acquisition, Goodwill Impairment and Long-lived Asset Impairment	3 Months Ended
Mar. 31, 2012
Acquisitions and Goodwill and Long-Lived Asset Impairment [Abstract]
Acquisition, Goodwill Impairment and Long-lived Asset Impairment	Acquisition, Goodwill Impairment and Long-lived Asset Impairment While the Company uses best estimates and assumptions as part of the purchase price allocation process to value assets acquired and liabilities assumed at the business combination date, estimates and assumptions are subject to refinement. As a result, during the preliminary purchase price allocation period, which may be up to one year from the business combination date, the Company records adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. The Company records adjustments to assets acquired or liabilities assumed subsequent to the purchase price allocation period in the operating results in the period in which the adjustments were determined. In the three month period ended March 31, 2012, the Company recorded a $0.6 million reduction in the fair value of royalty payments to RTM with a corresponding decrease of $0.4 million to goodwill and $0.2 million decrease to intangible assets. The total purchase price allocated to the tangible assets acquired was assigned based on the fair values as of the date of the acquisition. The fair value assigned to identifiable intangible assets acquired was determined using the income approach which discounts expected future cash flows to present value using estimated assumptions determined by management. The Company believes that these identified intangible assets will have no residual value after their estimated economic useful lives. Acquisition of Nanda Technologies GmbH in 2011 On November 21, 2011, the Company acquired 100% of the outstanding shares of Nanda Technologies GmbH (“Nanda”), a privately-held company with headquarters near Munich, Germany. The total purchase price consisted of approximately $25.2 million in cash, subject to certain post-closing adjustments associated with Nanda's working capital as of the acquisition date. As a result of the acquisition, the Company obtained a new technology and product line which enables the capture of full-wafer surface inspection images at high-volume production speeds. The technology is expected to enable the Company to address a significant market opportunity incremental to the metrology segments currently served by the Company's optical process control products. The transaction met the conditions of a business combination under ASC 805 and was accounted for under this guidance. With the Nanda acquisition, the Company recorded approximately $12 million of goodwill as the purchase price exceeded the fair value allocated to net tangible assets and identifiable intangible assets at March 31, 2012. Goodwill Impairment and Long-lived Asset Impairment The Company’s impairment review process is completed as of November 30th of each year or whenever events or circumstances occur which indicate that an impairment may have occurred. The accounting standard update provides the option to assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If, after assessing the qualitative factors, a company determines that it is not more likely than not that the fair value of a reporting unit is less than its carrying value, then performing the two-step impairment test is unnecessary. However, if a company concludes otherwise, then it is required to perform the first step of the two-step goodwill impairment test. The Company completed its annual goodwill impairment assessment as of November 30, 2011 by first performing a qualitative assessment. As part of this assessment, the Company considered the trading value of the Company's stock and the implied value of the Company as compared to the Company's net assets as well as the valuation of Nanda that was performed as of the acquisition on November 21, 2011. The Company concluded that it was not more likely than not that the fair value was less than the carrying values of the Company's reporting unit and therefore did not proceed to the Step 1 of the goodwill impairment test. The process of evaluating the potential impairment of long-lived assets is highly subjective and requires significant judgment. In estimating the fair value of these assets, the Company made estimates and judgments about future revenues and cash flows. The Company’s forecasts were based on assumptions that are consistent with the plans and estimates the Company is using to manage its business. Changes in these estimates could change the Company’s conclusion regarding impairment of the long-lived assets and potentially result in future impairment charges for all or a portion of their balance at December 31, 2011. The Company did not record any impairment charges in the fiscal year 2011.

Acquisition, Goodwill Impairment and Long-lived Asset Impairment

While the Company uses best estimates and assumptions as part of the purchase price allocation process to value assets acquired and liabilities assumed at the business combination date, estimates and assumptions are subject to refinement. As a result, during the preliminary purchase price allocation period, which may be up to one year from the business combination date, the Company records adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. The Company records adjustments to assets acquired or liabilities assumed subsequent to the purchase price allocation period in the operating results in the period in which the adjustments were determined. In the three month period ended March 31, 2012, the Company recorded a $0.6 million reduction in the fair value of royalty payments to RTM with a corresponding decrease of $0.4 million to goodwill and $0.2 million decrease to intangible assets.

The total purchase price allocated to the tangible assets acquired was assigned based on the fair values as of the date of the acquisition. The fair value assigned to identifiable intangible assets acquired was determined using the income approach which discounts expected future cash flows to present value using estimated assumptions determined by management. The Company believes that these identified intangible assets will have no residual value after their estimated economic useful lives.

Acquisition of Nanda Technologies GmbH in 2011

On November 21, 2011, the Company acquired 100% of the outstanding shares of Nanda Technologies GmbH (“Nanda”), a privately-held company with headquarters near Munich, Germany. The total purchase price consisted of approximately $25.2 million in cash, subject to certain post-closing adjustments associated with Nanda's working capital as of the acquisition date. As a result of the acquisition, the Company obtained a new technology and product line which enables the capture of full-wafer surface inspection images at high-volume production speeds. The technology is expected to enable the Company to address a significant market opportunity incremental to the metrology segments currently served by the Company's optical process control products. The transaction met the conditions of a business combination under ASC 805 and was accounted for under this guidance. With the Nanda acquisition, the Company recorded approximately $12 million of goodwill as the purchase price exceeded the fair value allocated to net tangible assets and identifiable intangible assets at March 31, 2012.

Goodwill Impairment and Long-lived Asset Impairment

The Company’s impairment review process is completed as of November 30th of each year or whenever events or circumstances occur which indicate that an impairment may have occurred. The accounting standard update provides the option to assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If, after assessing the qualitative factors, a company determines that it is not more likely than not that the fair value of a reporting unit is less than its carrying value, then performing the two-step impairment test is unnecessary. However, if a company concludes otherwise, then it is required to perform the first step of the two-step goodwill impairment test.

The Company completed its annual goodwill impairment assessment as of November 30, 2011 by first performing a qualitative assessment. As part of this assessment, the Company considered the trading value of the Company's stock and the implied value of the Company as compared to the Company's net assets as well as the valuation of Nanda that was performed as of the acquisition on November 21, 2011. The Company concluded that it was not more likely than not that the fair value was less than the carrying values of the Company's reporting unit and therefore did not proceed to the Step 1 of the goodwill impairment test.

The process of evaluating the potential impairment of long-lived assets is highly subjective and requires significant judgment. In estimating the fair value of these assets, the Company made estimates and judgments about future revenues and cash flows. The Company’s forecasts were based on assumptions that are consistent with the plans and estimates the Company is using to manage its business. Changes in these estimates could change the Company’s conclusion regarding impairment of the long-lived assets and potentially result in future impairment charges for all or a portion of their balance at December 31, 2011. The Company did not record any impairment charges in the fiscal year 2011.