Basis of Presentation, Nature of Operations and Summary of Significant Accounting Policies Investments Policy (Details)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Maximum Time Until Maturity of Short-term Available-for-Sale Investments	1 year
Maximum Time Until Maturity of Long-term Available-for-Sale Investments	2 years