Earnings per Share (Schedule of Earnings per Share, Basic and Diluted) (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Weighted average common shares outstanding, used in computing basic earnings per share	70,162	69,807	68,756
Effect of dilutive stock options and restricted stock units	902	874	678
Weighted-average common shares outstanding, used in computing diluted earnings per share	71,064	70,681	69,434
Basic	$ 2.48	$ 1.97	$ 1.37
Diluted	$ 2.45	$ 1.94	$ 1.36