Commitments and Contingencies Extended Warranty (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Less: current portion of unearned revenue for extended warranty	$ 80,342		$ 80,342		$ 73,301
Extended Warranty [Member]
Beginning balance	33,068	$ 34,084	33,654	$ 34,138
Unearned revenue for new extended warranties	352	826	1,366	2,251
Unearned revenue recognized	(905)	(716)	(2,640)	(2,029)
Effect of change in exchange rates	(31)	(187)	104	(353)
Ending balance	32,484	34,007	32,484	34,007
Less: current portion of unearned revenue for extended warranty	4,134	3,416	4,134	3,416
Long-term unearned revenue for extended warranty within other long-term obligations	$ 28,350	$ 30,591	$ 28,350	$ 30,591

Total increase or decrease in the deferred revenue liability due to currency translation.

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Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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The carrying amount of consideration received or receivable as of the balance sheet date on potential earnings that were not recognized as revenue in conformity with GAAP, and which are expected to be recognized as such within one year or the normal operating cycle, if longer, including sales, license fees, and royalties, but excluding interest income.

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The noncurrent portion of deferred revenue amount as of balance sheet date. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is not expected to be recognized in the next twelve months. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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