Supplemental Cash Flow Information (Reconciliation of Cash, Cash Equivalents and Restricted Cash to Statement of Cash Flows) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
Cash and cash equivalents	$ 53,336	$ 35,594
Restricted cash	1,612	4,877
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 54,948	$ 40,471	$ 67,633