Earnings Per Share (Details) - $ / shares shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Weighted average shares outstanding: [Abstract]
Basic (in shares)	40,125	39,479
Effect of dilutive securities: [Abstract]
Stock options and employee stock purchase plan (in shares)	830	1,217
Diluted (in shares)	40,955	40,696
Basic (in dollars per share)	$ 0.77	$ 0.83
Diluted (in dollars per share)	$ 0.75	$ 0.80
Anti-dilutive stock options excluded from diluted earnings per share computations (in shares)	66	65