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Basis of Presentation and Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified | 9 Months Ended | 12 Months Ended | 9 Months Ended | 12 Months Ended | 9 Months Ended | 12 Months Ended | 3 Months Ended | 9 Months Ended
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Sep. 30, 2013 Customer Concentration Risk [Member] Customer | Sep. 30, 2012 Customer Concentration Risk [Member] Customer | Dec. 31, 2012 Customer Concentration Risk [Member] Customer | Sep. 30, 2013 Revenues [Member] Customer Concentration Risk [Member] Customer 1 [Member] | Sep. 30, 2012 Revenues [Member] Customer Concentration Risk [Member] Customer 1 [Member] | Sep. 30, 2013 Revenues [Member] Customer Concentration Risk [Member] Customer 2 [Member] | Sep. 30, 2012 Revenues [Member] Customer Concentration Risk [Member] Customer 2 [Member] | Sep. 30, 2013 Accounts Receivable [Member] Customer Concentration Risk [Member] Customer 1 [Member] | Dec. 31, 2012 Accounts Receivable [Member] Customer Concentration Risk [Member] Customer 1 [Member] | Sep. 30, 2013 Accounts Receivable [Member] Customer Concentration Risk [Member] Customer 2 [Member] | Dec. 31, 2012 Accounts Receivable [Member] Customer Concentration Risk [Member] Customer 2 [Member] | Sep. 30, 2012 Property equipment building and leasehold improvements [Member] | Sep. 30, 2012 Property equipment building and leasehold improvements [Member]
Long-Lived Assets to be Abandoned [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Accelerated depreciation |  |  |  |  |  |  |  |  |  |  |  | $ 0.1 | $ 1.4
Impairment loss |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.8
Concentration Risk [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of major customers | 2 | 2 | 2 |  |  |  |  |  |  |  |  |  |
Concentration risk, percentage (in hundredths) |  |  |  | 57.00% | 45.00% | 30.00% | 35.00% | 27.00% | 58.00% | 50.00% | 35.00% |  |

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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 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13537-108611 Reference 2: 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 3: 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=28364263&loc=d3e13531-108611 Reference 4: 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 + Details
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- Definition The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2611-110228 + Details
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