| Satellites | Property and other equipment | Assets under construction | Total | |||||||||||||
| Cost as at January 1, 2016 | $ | 3,213,581 | $ | 233,675 | $ | 48,057 | $ | 3,495,313 | ||||||||
| Additions | — | 1,736 | 227,222 | 228,958 | ||||||||||||
| Disposals/retirements | — | (12,100 | ) | — | (12,100 | ) | ||||||||||
| Reclassifications and transfers from assets under construction | — | 6,130 | (6,130 | ) | — | |||||||||||
| Impact of foreign exchange | (10,478 | ) | (233 | ) | 1,619 | (9,092 | ) | |||||||||
| Cost as at December 31, 2016 and January 1, 2017 | 3,203,103 | 229,208 | 270,768 | 3,703,079 | ||||||||||||
| Additions | — | 3,270 | 139,212 | 142,482 | ||||||||||||
| Disposals/retirements | — | (2,982 | ) | — | (2,982 | ) | ||||||||||
| Reclassifications and transfers from assets under construction | — | 11,816 | (11,816 | ) | — | |||||||||||
| Impact of foreign exchange | (22,925 | ) | (2,092 | ) | (21,199 | ) | (46,216 | ) | ||||||||
| Cost as at December 31, 2017 | $ | 3,180,178 | 239,220 | 376,965 | 3,796,363 | |||||||||||
| Accumulated depreciation and impairment as at January 1, 2016 | $ | (1,438,995 | ) | $ | (131,053 | ) | $ | — | $ | (1,570,048 | ) | |||||
| Depreciation | (209,804 | ) | (14,969 | ) | — | (224,773 | ) | |||||||||
| Disposals/retirements | — | 9,535 | — | 9,535 | ||||||||||||
| Impact of foreign exchange | (2,522 | ) | 140 | — | (2,382 | ) | ||||||||||
| Accumulated depreciation and impairment as at December 31, 2016 and January 1, 2017 | (1,651,321 | ) | (136,347 | ) | — | (1,787,668 | ) | |||||||||
| Depreciation | (206,439 | ) | (14,619 | ) | — | (221,058 | ) | |||||||||
| Disposals/retirements | — | 2,564 | — | 2,564 | ||||||||||||
| Impact of foreign exchange | 568 | 1,078 | — | 1,646 | ||||||||||||
| Accumulated depreciation and impairment as at December 31, 2017 | $ | (1,857,192 | ) | $ | (147,324 | ) | $ | — | $ | (2,004,516 | ) | |||||
| Net carrying values | ||||||||||||||||
| As at December 31, 2016 | $ | 1,551,782 | $ | 92,861 | $ | 270,768 | $ | 1,915,411 | ||||||||
| As at December 31, 2017 | $ | 1,322,986 | $ | 91,896 | $ | 376,965 | $ | 1,791,847 | ||||||||