Disclosures About Fair Value - Fair Value of Assets and Liabilities on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets
Available-for-sale securities	$ 26,788	$ 31,032
Fair Value, Measurements, Recurring
Assets
Available-for-sale securities	18,225	21,990
Available-for-sale debt maturities	5,901	6,380
Liabilities
Contingent consideration	3,737	3,902
Fair Value, Measurements, Recurring \| Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets
Available-for-sale securities	11,106	10,892
Available-for-sale debt maturities	5,901	6,380
Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Assets
Available-for-sale securities	$ 7,119	$ 11,098
Available-for-sale debt maturities
Fair Value, Measurements, Recurring \| Significant Unobservable Inputs (Level 3)
Liabilities
Contingent consideration	$ 3,737	$ 3,902
Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Level 1 to Level 2 transfers		$ 5,600

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount of available-for-sale debt securities at fair value that do not have a single maturity date and which the entity has decided to disclose separately rather than allocating the fair value over several maturity groupings.

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Amount of liability recognized arising from contingent consideration in a business combination.

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Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

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