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
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Operating lease costs	$ 2,118	$ 1,646
Short-term lease costs	266	64
Total lease cost	$ 2,384	$ 1,710