Intangible Assets

12 Months Ended

Dec. 31, 2019

Intangible assets

Intangible Assets

18.   Intangible assets

			Accumulated
As at December 31, 2019	Cost		amortization		Net book value
Trade names and trademarks	$	53,319	$	(2,028)	$	51,291
Customer relationships		124,865		(34,666)		90,199
Software		157,776		(78,330)		79,446
Software under development		12,444		—		12,444
	$	348,404	$	(115,024)	$	233,380

			Accumulated
As at December 31, 2018	Cost		amortization		Net book value
Trade names and trademarks	$	53,409	$	(1,201)	$	52,208
Customer relationships		124,986		(22,010)		102,976
Software		127,320		(48,522)		78,798
Software under development		11,640		—		11,640
	$	317,355	$	(71,733)	$	245,622

During the year ended December 31, 2019, the Company recognized an impairment loss of nil (2018: nil; 2017: the Company recorded an impairment loss relating to certain software and software under development $8,911,000) (note 7).

At December 31, 2019, a net carrying amount of $62,589,000 (December 31, 2018: $61,883,000) included in intangible assets was not subject to amortization. During the year ended December 31, 2019, the cost of additions was reduced by $1,022,000 for recognition of tax credits (2018: $1,606,000; 2017: $888,000).

During the year ended December 31, 2019, interest of $402,000 (2018: $460,000; 2017: $281,000) was capitalized to the cost of software under development. These interest costs relating to qualifying assets are capitalized at a weighted average rate of 4.01% (2018: 4.09%; 2017: 3.18%).

During the year ended December 31, 2019, the weighted average amortization period for all classes of intangible assets was 7.8 years (2018: 8.2; 2017: 7.9 years).

18.   Intangible assets (continued)

As at December 31, 2019, estimated annual amortization expense for the next five years ended December 31 are as follows:

2020	$	35,539
2021		29,706
2022		23,438
2023		17,214
2024		10,139
	$	116,036