Summary of Significant Accounting Policies (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jan. 01, 2017	Dec. 31, 2016
Fair value measurements
Amount of transfers between levels within the fair value hierarchy			$ 0	$ 0
Research and Development
Research and development expenses	$ 8,302,000	$ 9,030,000	23,444,000	23,524,000
Capitalized Software Costs
Expenditures for externally marketed software			(25,447,000)	(17,991,000)
New Accounting Pronouncements
Accumulated net unrealized gains on available-for-sale equity securities	13,600,000		13,600,000
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	35,855,000	32,911,000	73,221,000	112,549,000
Net Income (Loss) Available to Common Stockholders, Basic	34,669,000	36,644,000	80,533,000	143,451,000
Accounting Standards Update 2016-09
New Accounting Pronouncements
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	200,000		1,600,000
Net Income (Loss) Available to Common Stockholders, Basic	200,000		4,800,000
Accumulated Earnings | Accounting Standards Update 2016-09
New Accounting Pronouncements
Cumulative effect of adoption of ASU 2016-09 as of January 1, 2017					$ 14,500,000
Other noncurrent assets, net
Capitalized Software Costs
Net carrying amount of externally marketed software	87,700,000		87,700,000			$ 76,300,000
Externally marketed software under development and not yet placed in service	16,700,000		16,700,000			50,100,000
Expenditures for externally marketed software	(8,300,000)	(6,200,000)	(25,400,000)	(18,500,000)
Amortization expense relating to the development of externally marketed software	5,500,000	2,500,000	$ 14,100,000	7,200,000
Maximum
Capitalized Software Costs
Software useful life			5 years
Weighted Average
Capitalized Software Costs
Software useful life			4 years
Cost of Sales
Research and Development
Research and development expenses	7,000,000.0	11,100,000	$ 20,700,000	17,200,000
Research and Development Expense
Research and Development
Research and development expenses	8,300,000	$ 9,000,000.0	23,400,000	$ 23,500,000
Level 2
Fair value measurements
Orbital incentive obligations	$ 113,500,000		$ 113,500,000			$ 74,100,000
6 1/2% Senior Secured Notes due 2019
Fair value measurements
Interest rate	6.50%		6.50%			6.50%
7 5/8% Senior Unsecured Notes due 2021
Fair value measurements
Interest rate	7.625%		7.625%			7.625%
5 1/4% Senior Secured Notes due 2026
Fair value measurements
Interest rate	5.25%		5.25%			5.25%
6 5/8% Senior Unsecured Notes due 2026
Fair value measurements
Interest rate	6.625%		6.625%			6.625%