Earnings Per Share - Narrative (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Incremental common shares attributable to dilutive effect of share-based payment arrangements	907	707	916	549
Antidilutive securities excluded from computation of earnings per share, amount (approximately)	1	175	4	178