Income Taxes (Provision (Benefit) For Income Taxes) (Details) $ in Thousands, CAD in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Oct. 31, 2016 CAD	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Income Taxes [Abstract]
U.S. Federal - Current			$ 1,283	$ 85	$ 84
U.S. Federal - Deferred			(786)	0	0
Provision for U.S. federal income taxes			497	85	84
Foreign - Current			3,094	1,898	2,875
Foreign - Deferred			969	(196)	(1,305)
Provision for foreign income taxes			4,063	1,702	1,570
Total provision for income taxes	CAD 2.2	$ 5,700	$ 4,560	$ 1,787	$ 1,654