Income Per Share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Schedule of Weighted Average Number of Shares Outstanding Used to Compute Income Per Share

The weighted average numbers of shares outstanding used to compute income per share amounts were as follows (in thousands):

	Year Ended December 31,
	2017	2016	2015
Shares used for basic per share calculations	30,671	31,032	31,288
Dilutive effect of outstanding options, RSUs, and PSUs	339	269	301
Shares used for diluted per share calculations	31,010	31,301	31,589

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The weighted average numbers of shares outstanding listed in the table below were anti-dilutive and excluded from the computation of diluted income per share, primarily because the average market price did not exceed the exercise price. These shares may be dilutive potential common shares in the future (in thousands):

	As of December 31,
	2017	2016	2015
Stock options	8	8	12