Debt Obligations - Schedule of Debt (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Apr. 16, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total lease liability balance	$ 1.4	$ 1.4		$ 1.7
Total aggregate finance lease and debt payments	711.7	711.7		805.0
Issuance discount, net and deferred financing costs	(25.7)	(25.7)		(31.4)
Total debt obligations	686.0	686.0		773.6
11.50% Senior Secured Notes, due 2021
Debt Instrument [Line Items]
Outstanding debt	$ 76.9	$ 76.9
Interest rate (as a percent)	11.50%	11.50%
LIBOR | DBM Global Credit Facilities | LIBOR plus 5.85% Note, due 2023
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)		5.85%
LIBOR | DBM Global Credit Facilities | LIBOR plus 1.50% Line of Credit | Real Estate Term Advance | Revolving Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)		150.00%
Construction | LIBOR | LIBOR plus 5.85% Note, due 2023 | Real Estate Term Advance
Debt Instrument [Line Items]
Outstanding debt	$ 75.6	$ 75.6		77.0
Construction | LIBOR | LIBOR plus 1.50% Line of Credit | Real Estate Term Advance
Debt Instrument [Line Items]
Outstanding debt	49.7	49.7		48.9
Construction | LIBOR | Obligations under finance leases | Real Estate Term Advance
Debt Instrument [Line Items]
Outstanding debt	0.2	0.2		0.2
Energy | Obligations under finance leases
Debt Instrument [Line Items]
Other, various maturity dates	3.0	3.0		2.4
Energy | LIBOR plus 3.0% Term Loan due in 2023
Debt Instrument [Line Items]
Outstanding debt	26.3	26.3		27.1
Energy | 5.00% Term Loan due in 2022
Debt Instrument [Line Items]
Outstanding debt	$ 10.9	$ 10.9		11.2
Interest rate (as a percent)	5.00%	5.00%
Energy | 4.50% Note due in 2022
Debt Instrument [Line Items]
Outstanding debt	$ 9.9	$ 9.9		10.2
Interest rate (as a percent)	4.50%	4.50%
Energy | LIBOR | American Natural Gas [Member] | LIBOR plus 3.0% Term Loan due in 2023
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)		3.00%
Broadcasting
Debt Instrument [Line Items]
Total lease liability balance	$ 1.2	$ 1.2		1.4
Broadcasting | 10.50% Note due 2020
Debt Instrument [Line Items]
Outstanding debt	$ 42.5	$ 42.5		42.5
Interest rate (as a percent)	10.50%	10.50%
Broadcasting | Other, various maturity dates
Debt Instrument [Line Items]
Outstanding debt	$ 5.1	$ 5.1		7.9
Broadcasting | Tranche A Senior Notes, Due October 2020
Debt Instrument [Line Items]
Outstanding debt	$ 39.3	$ 39.3		36.2
Broadcasting | Senior Notes Due October 2019, 8.5%
Debt Instrument [Line Items]
Interest rate (as a percent)	8.50%	8.50%
Non-Operating Corporate | 11.50% Senior Secured Notes, due 2021
Debt Instrument [Line Items]
Outstanding debt	$ 393.0	$ 393.0		470.0
Interest rate (as a percent)	11.50%	11.50%
Non-Operating Corporate | 7.50% Convertible Senior Notes, due 2022
Debt Instrument [Line Items]
Outstanding debt	$ 55.0	$ 55.0		55.0
Interest rate (as a percent)	7.50%	7.50%
Non-Operating Corporate | LIBOR plus 6.75% Line of Credit(1)
Debt Instrument [Line Items]
Outstanding debt	$ 0.0	$ 0.0		$ 15.0
Basis spread on variable rate (as a percent)	6.75%	6.75%
Non-Operating Corporate | LIBOR plus 6.75% Line of Credit(1) | Subsequent Event
Debt Instrument [Line Items]
Outstanding debt			$ 10.0