Earnings Per Share Securities Excluded Due to Exercise Price Exceeding Average Price During Period (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Shares Excluded Due to Exercise Price Exceeding Average Price During Period [Line Items]
Shares Excluded Due to Exercise Price Exceeding Average Price During Period	16	54	136	87
Outstanding Stock Awards [Member]
Shares Excluded Due to Exercise Price Exceeding Average Price During Period [Line Items]
Shares Excluded Due to Exercise Price Exceeding Average Price During Period	16	54	136	87