Fair Value Notes Receivable (Policies)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]	As of June 30, 2018 and December 31, 2017, the Company's other long-term assets balance included a $2.5 million note receivable, recorded at its estimated collectible amount. The Company estimates that the carrying value of the note receivable approximates its fair value. The estimated fair value represents a Level 3 measurement within the fair value hierarchy, and is based on market interest rates and the assessed creditworthiness of the third party. The Company estimates the fair value of its long-term debt based upon rates currently available to the Company for debt with similar terms and remaining maturities. This is a Level 3 measurement. Based upon the terms of the debt, the carrying amount of long-term debt approximated fair value at June 30, 2018 and December 31, 2017.