Supplemental Cash Flow Information (Reconciliation of Cash, Cash Equivalents and Restricted Cash to Statement of Cash Flows) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Supplemental Cash Flow Information [Abstract]
Cash and cash equivalents	$ 67,165	$ 53,336	$ 65,490
Restricted cash	1,732	1,612	3,322
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 68,897	$ 54,948	$ 68,812	$ 40,471