Long-term debt (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure of detailed information about borrowings [line items]

Disclosure of borrowings [Table Text Block]

		Dec. 31, 2020			Dec. 31, 2019
Senior unsecured notes (a)	$	1,139,695		$	991,558
Less: Unamortized transaction costs - revolving credit facilities (b)		(4,020	)		(6,303	)
	$	1,135,675		$	985,255

Senior unsecured notes [Member]

Disclosure of detailed information about borrowings [line items]

Disclosure of detailed information about borrowings [Table Text Block]

Balance, January 1, 2019	$	989,306
Change in fair value of embedded derivative (prepayment option)		1,079
Accretion of transaction costs and premiums		1,173
Balance, December 31, 2019	$	991,558
Addition to Principal, net of $8,176 transaction costs		591,824
Principal repayments		(400,000	)
Change in fair value of embedded derivative (prepayment option)		(47,169	)
Write-down of unamortized transaction costs		2,315
Accretion of transaction costs and premiums		1,167
Balance, December 31, 2020	$	1,139,695

Unamortized transaction costs - revolving credit facilities [Member]

Disclosure of detailed information about borrowings [line items]

Disclosure of detailed information about unamortized transaction costs revolving credit facilities [Table Text Block]

Balance, January 1, 2019	$	8,276
Accretion of transaction costs		(2,342	)
Transaction costs		369
Balance, December 31, 2019	$	6,303
Accretion of transaction costs		(3,062	)
Write-down of unamortized transaction costs		(1,502	)
Transaction costs		2,281
Balance, December 31, 2020 1	$	4,020
1 Balance, representing deferred transaction costs, is in an asset position.