Stock-Based Compensation Employee Stock Purchase Plan (Details) - shares		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Stock [Member]
[Line Items]
Shares of stock sold to employees(1)	[1]	20	54	61

[1] Stock sold to employees during each fiscal quarter under the ESPP is associated with the offering period ending on the last day of the previous fiscal quarter.