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Concentrations of Credit Risk and Major Customers (Details) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2015 USD ($) | Sep. 30, 2015 USD ($) | Jun. 30, 2015 USD ($) | Mar. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) | Sep. 30, 2014 USD ($) | Jun. 30, 2014 USD ($) | Mar. 31, 2014 USD ($) | Dec. 31, 2015 USD ($) Customer | Dec. 31, 2014 USD ($) Customer | Dec. 31, 2013 USD ($) Customer
Concentration Risk |  |  |  |  |  |  |  |  |  |  |
Concentration of risk, number of customers |  |  |  |  |  |  |  |  | 5 |  |
Entity-Wide Revenue, Major Customer, Amount | $ | $ 174,605 | $ 182,533 | $ 191,684 | $ 187,523 | $ 202,997 | $ 217,092 | $ 226,785 | $ 224,481 | $ 736,345 | $ 871,355 | $ 582,257
Sales Revenue, Services, Net [Member] | Customer Concentration Risk [Member] |  |  |  |  |  |  |  |  |  |  |
Concentration Risk |  |  |  |  |  |  |  |  |  |  |
Concentration of risk, number of customers |  |  |  |  |  |  |  |  | 0 | 0 | 0
Baseline percentage for customer concentration of risk |  |  |  |  |  |  |  |  | 10.00% | 10.00% | 10.00%
Concentration Risk, Percentage |  |  |  |  |  |  |  |  | 36.00% | 32.00% | 32.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] |  |  |  |  |  |  |  |  |  |  |
Concentration Risk |  |  |  |  |  |  |  |  |  |  |
Concentration Risk, Percentage |  |  |  |  |  |  |  |  | 33.00% | 28.00% |

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- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13537-108611 + Details
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