Earnings per share (Tables)

12 Months Ended

Dec. 31, 2015

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,
	2015	2014	2013
Weighted average number of common shares outstanding used to compute basic earnings per share	52,259	53,437	53,481
Dilutive effect of stock-based awards	746	857	1,074
Number of shares used to compute diluted earnings per share	53,005	54,294	54,555