Leases (Components of Lease Cost Reported in General and Administrative Expenses in Unaudited Condensed Consolidated Statements of Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease costs	$ 2,285	$ 1,897	$ 6,524	$ 5,101
Short-term lease costs	147	222	575	382
Total lease cost	$ 2,432	$ 2,119	$ 7,099	$ 5,483