Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019
Subsequent events
Cost of shares repurchased		$ 340	$ 290	$ 2,303	$ 2,016
2019 Stock Repurchase Program
Subsequent events
Shares authorized under repurchase program						2,000,000
Number of shares repurchased				1,000,000
Subsequent event | 2019 Stock Repurchase Program
Subsequent events
Number of shares repurchased	165,000
Share Price	$ 74.88
Cost of shares repurchased	$ 12,400
Additional shares available for repurchase	835,000