Fair Value of Financial Instruments	12 Months Ended
Fair Value of Financial Instruments	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	(18) Fair Value of Financial Instruments At December 31, 2017 and 2016, the Company’s financial instruments included cash and cash equivalents, marketable securities, accounts receivable, investments, accounts payable and borrowings. The fair values of cash and cash equivalents, accounts receivable, accounts payable and short-term borrowings and current portion of long-term debt approximated carrying values because of the short-term nature of these instruments. Investments and initial recognition of asset retirement obligations are reported at fair values. Fair values for investments held at cost are not readily available, but are estimated to approximate fair value. The estimated fair value of the Company’s long term debt (including current maturities) was $2,666,875, which exceeded both the gross and carrying amount of $2,585,409 as of December 31, 2017. The majority of the fair value is determined using observed prices of publicly traded debt (level 1 in the fair value hierarchy) and the remaining is valued based on quoted prices for similar debt (level 2 in the fair value hierarchy).

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.