Earnings per share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Reconciliation of Shares Used to Compute Basic and Diluted Earnings per Share

The following is a reconciliation of the shares used to compute basic and diluted earnings per share (in thousands):

	Year Ended December 31,
	2016	2015	2014
Weighted average number of common shares outstanding used to compute basic earnings per share	53,192	52,259	53,437
Dilutive effect of stock-based awards	555	746	857
Number of shares used to compute diluted earnings per share	53,747	53,005	54,294