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Accounting Policies (Narrative) (Details) $ in Thousands | 12 Months Ended
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Dec. 31, 2015 USD ($) Segment | Dec. 31, 2014 USD ($) | Dec. 31, 2013 USD ($)
Accounting Policies [Abstract] |  |  |
Number of reportable segments | Segment | 4 |  |
Insurance policy duration | 1 year |  |
Recorded allowances for credit losses (less than) | $ 1,500 | $ 1,500 |
Estimated credit losses | 600 | 600 |
Account write offs (up to) | 600 | 600 |
Earned But unbilled premiums | $ 3,900 | 3,400 |
Minimum period for claims resolution | 5 years |  |
Percentage of tax benefit | 50.00% |  |
Property, Plant and Equipment [Line Items] |  |  |
Depreciation | $ 7,437 | 6,956 | $ 4,538
Estimated aggregate amortization of intangible assets for 2016 | 8,100 |  |
Estimated aggregate amortization of intangible assets for 2017 | 5,600 |  |
Estimated aggregate amortization of intangible assets for 2018 | 5,600 |  |
Estimated aggregate amortization of intangible assets for 2019 | 5,600 |  |
Estimated aggregate amortization of intangible assets for 2020 | 5,600 |  |
Building and Building Improvements [Member] |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Real estate accumulated depreciation | 24,200 | 23,000 |
Depreciation | $ 1,500 | $ 1,500 | $ 1,500

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