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Summary of Significant Accounting Policies (Details) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2014 USD ($) | Dec. 31, 2016 USD ($) item | Dec. 31, 2015 USD ($) | Sep. 30, 2014 USD ($)
Significant Accounting Policies |  |  |  |
Number of states in which the Company operates | item |  | 48 |  |
Depreciation | $ 9,736,000 | $ 44,283,000 | $ 47,072,000 | $ 40,168,000
Impairment of long-lived assets | $ 0 | $ 0 | $ 0 | $ 0
Federal statutory effective income tax rate | 35.00% | 35.00% | 35.00% | 35.00%
Impairment of Intangible Assets |  | $ 0 | $ 0 |
Change in estimated life of certain recording equipment assets |  |  |  |
Significant Accounting Policies |  |  |  |
Depreciation |  | $ 1,300,000 |  |

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- Definition The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. + 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=66902209&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 + Details
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- Definition Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275 + Details
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