Stock-Based Compensation (Details 2)	12 Months Ended
	Dec. 31, 2018 $ / shares shares
$11.45 to $15.83
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares | shares	44,760
Options Outstanding, Average Remaining Life (Years)	9 months 4 days
Options Outstanding, Average Exercise Price	$ 14.19
Options Exercisable, Number of Shares | shares	44,760
Options Exercisable, Average Exercise Price	$ 14.19
Range of Exercise Prices, Lower Range Limit	11.45
Range of Exercise Prices, Upper Range Limit	$ 15.83
$20.69 to $26.32
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares | shares	73,460
Options Outstanding, Average Remaining Life (Years)	3 years 4 months 21 days
Options Outstanding, Average Exercise Price	$ 23.73
Options Exercisable, Number of Shares | shares	73,460
Options Exercisable, Average Exercise Price	$ 23.73
Range of Exercise Prices, Lower Range Limit	20.69
Range of Exercise Prices, Upper Range Limit	$ 26.32
$26.59 to $34.92
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares | shares	164,117
Options Outstanding, Average Remaining Life (Years)	6 years 10 months 17 days
Options Outstanding, Average Exercise Price	$ 31.11
Options Exercisable, Number of Shares | shares	111,425
Options Exercisable, Average Exercise Price	$ 30.98
Range of Exercise Prices, Lower Range Limit	26.59
Range of Exercise Prices, Upper Range Limit	$ 34.92
$36.31 to $38.93
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares | shares	171,247
Options Outstanding, Average Remaining Life (Years)	5 years 9 months
Options Outstanding, Average Exercise Price	$ 36.64
Options Exercisable, Number of Shares | shares	169,900
Options Exercisable, Average Exercise Price	$ 36.62
Range of Exercise Prices, Lower Range Limit	36.31
Range of Exercise Prices, Upper Range Limit	$ 38.93
$38.93 to $63.38
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares | shares	230,565
Options Outstanding, Average Remaining Life (Years)	8 years 6 months
Options Outstanding, Average Exercise Price	$ 52.71
Options Exercisable, Number of Shares | shares	43,861
Options Exercisable, Average Exercise Price	$ 45.98
Range of Exercise Prices, Lower Range Limit	38.93
Range of Exercise Prices, Upper Range Limit	$ 63.38