Debt (Tables)

3 Months Ended

Mar. 31, 2019

Debt [Abstract]

Schedule of Debt

			Carrying amount
			March 31,		December 31,
				2019		2018
Short-term debt			$	8,687	$	19,896
Long-term debt:
	Term loans:
		Denominated in Canadian dollars, secured, bearing interest at a weighted
		average rate of 4.342%, due in monthly installments of interest only and
		quarterly installments of principal, maturing in October 2021		163,189		161,891
		Denominated in United States dollars, secured, bearing interest at a weighted
		average rate of 4.606%, due in weekly installments of interest only and
		quarterly installments of principal, maturing in October 2021		52,690		62,690
		Less: unamortized debt issue costs		(2,121)		(2,419)
	Senior unsecured notes:
		Bearing interest at 5.375% due in semi-annual installments, with the full
		amount of principal due in January 2025		500,000		500,000
		Less: unamortized debt issue costs		(10,421)		(10,864)
Total long-term debt				703,337		711,298
Total debt			$	712,024	$	731,194
Long-term debt:
Current portion			$	15,648	$	13,126
Non-current portion				687,689		698,172
Total long-term debt			$	703,337	$	711,298