Income Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Income per share:
Basic weighted average shares outstanding	30,099	30,671	[1]	31,032	[1]
Dilutive potential common shares	256	339		269
Diluted weighted average shares outstanding	30,355	31,010	[1]	31,301	[1]
Stock options
Income per share:
Anti-dilutive securities excluded from computation of diluted income per share	10	8		8
RSUs
Income per share:
Anti-dilutive securities excluded from computation of diluted income per share	1	0		0

[1] See Note 4.