Stock-Based Compensation (Details 1) shares in Thousands	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Number of options (in thousands)
Options outstanding at beginning of period (in shares) | shares	3,064
Options granted (in shares) | shares	563
Options exercised (in shares) | shares	(383)
Options forfeited (in shares) | shares	(18)
Options expired (in shares) | shares	(1)
Options outstanding at end of period (in shares) | shares	3,225
Weighted average exercise price
Weighted average exercise price, Options outstanding Beginning Balance (usd per share) | $ / shares	$ 21.14
Weighted average exercise price, Options granted (usd per share) | $ / shares	29.68
Weighted average exercise price, Options exercised (usd per share) | $ / shares	13.84
Weighted average exercise price, Options forfeited (usd per share) | $ / shares	26.33
Weighted average exercise price, Options expired (usd per share) | $ / shares	26.86
Weighted average exercise price, Options outstanding Ending Balance (usd per share) | $ / shares	$ 23.48