Accounting Policies	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	2. Update to Significant Accounting PoliciesCash, Cash Equivalents, and Restricted Cash - We consider investments in highly liquid financial instruments purchased with an original stated maturity of 90 days or less and temporary investments of cash in short-term money market securities to be cash equivalents. Restricted cash primarily consists of amounts held in our non-qualified deferred compensation plan. Restricted cash is excluded from cash and cash equivalents and is included in other current or non-current assets.