Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]

At December 31, 2018, total future minimum lease payments required under operating leases having initial or remaining non-cancellable lease terms the next five years and thereafter are as follows:

(dollars in millions)
2019	$	10.9
2020	9.4
2021	6.1
2022	4.5
2023	3.9
Thereafter	23.7
Total	$	58.5

Finance Lease, Liability, Maturity [Table Text Block]

The future minimum payments under the base agreements, as well as the renewal options for each lease which the Company expects to exercise, are as follows:

(dollars in millions)
2019	$	0.8
2020	0.8
2021	3.5
2022	5.8
2023	5.8
Thereafter	58.8
Total minimum financing obligation payments	$	75.5

Schedule of Change in Asset Retirement Obligation [Table Text Block]

	December 31,
(dollars in millions)	2018			2017
Balance, beginning of period	$	2.3		$	1.8
Hawaiian Telcom opening balance sheet adjustment	6.6			—
Liabilities incurred	—			0.4
Liabilities settled	(0.1		)	—
Accretion expense	0.3			0.1
Balance, end of period	$	9.1		$	2.3