Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Voting Common Stock [Member] Common Stock [Member]	Nonvoting Common Stock [Member] Common Stock [Member]	Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Total
Balance at Dec. 31, 2017	$ 216	$ 95	$ 1,019,988	$ (9,592)	$ (682,831)	$ (37,278)	$ 290,598
Balance, shares at Dec. 31, 2017	21,582	9,506		154
Net income (loss)					4,294
Other comprehensive income (loss)						7,144
Comprehensive income (loss)							11,438
Cumulative effect adjustment attributable to investment in Telesat					(22,107)		(22,107)
Balance at Mar. 31, 2018	$ 216	$ 95	1,019,988	$ (9,592)	(700,644)	(30,134)	279,929
Balance, shares at Mar. 31, 2018	21,582	9,506		154
Balance at Dec. 31, 2017	$ 216	$ 95	1,019,988	$ (9,592)	(682,831)	(37,278)	290,598
Balance, shares at Dec. 31, 2017	21,582	9,506		154
Net income (loss)							4,741
Other comprehensive income (loss)							7,772
Comprehensive income (loss)							12,513
Balance at Jun. 30, 2018	$ 216	$ 95	1,019,988	$ (9,592)	(700,197)	(29,506)	281,004
Balance, shares at Jun. 30, 2018	21,582	9,506		154
Balance at Dec. 31, 2017	$ 216	$ 95	1,019,988	$ (9,592)	(682,831)	(37,278)	290,598
Balance, shares at Dec. 31, 2017	21,582	9,506		154
Other comprehensive income (loss)						23,831
Balance at Dec. 31, 2018	$ 216	$ 95	1,019,988	$ (9,592)	(695,521)	(17,620)	297,566
Balance, shares at Dec. 31, 2018	21,582	9,506		154
Balance at Mar. 31, 2018	$ 216	$ 95	1,019,988	$ (9,592)	(700,644)	(30,134)	279,929
Balance, shares at Mar. 31, 2018	21,582	9,506		154
Net income (loss)					447		447
Other comprehensive income (loss)						628	628
Comprehensive income (loss)							1,075
Balance at Jun. 30, 2018	$ 216	$ 95	1,019,988	$ (9,592)	(700,197)	(29,506)	281,004
Balance, shares at Jun. 30, 2018	21,582	9,506		154
Net income (loss)					4,873
Other comprehensive income (loss)						16,059
Comprehensive income (loss)							20,932
Tax Cuts and Jobs Act, reclassification tax effect					4,173	(4,173)
Cumulative effect adjustment attributable to investment in Telesat					(4,370)		(4,370)
Balance at Dec. 31, 2018	$ 216	$ 95	1,019,988	$ (9,592)	(695,521)	(17,620)	297,566
Balance, shares at Dec. 31, 2018	21,582	9,506		154
Net income (loss)					38,516
Other comprehensive income (loss)						(6,406)
Comprehensive income (loss)							32,110
Balance at Mar. 31, 2019	$ 216	$ 95	1,019,988	$ (9,592)	(657,005)	(24,026)	329,676
Balance, shares at Mar. 31, 2019	21,582	9,506		154
Balance at Dec. 31, 2018	$ 216	$ 95	1,019,988	$ (9,592)	(695,521)	(17,620)	297,566
Balance, shares at Dec. 31, 2018	21,582	9,506		154
Net income (loss)							76,743
Other comprehensive income (loss)						(13,052)	(13,052)
Comprehensive income (loss)							63,691
Balance at Jun. 30, 2019	$ 216	$ 95	1,019,988	$ (9,592)	(618,778)	(30,672)	361,257
Balance, shares at Jun. 30, 2019	21,582	9,506		154
Balance at Mar. 31, 2019	$ 216	$ 95	1,019,988	$ (9,592)	(657,005)	(24,026)	329,676
Balance, shares at Mar. 31, 2019	21,582	9,506		154
Net income (loss)					38,227		38,227
Other comprehensive income (loss)						(6,646)	(6,646)
Comprehensive income (loss)							31,581
Balance at Jun. 30, 2019	$ 216	$ 95	$ 1,019,988	$ (9,592)	$ (618,778)	$ (30,672)	$ 361,257
Balance, shares at Jun. 30, 2019	21,582	9,506		154