Subsequent Events - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Jul. 31, 2016	Jun. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
State jurisdiction
Subsequent Event [Line Items]
Operating loss carryforwards generated during the period		$ 6.3
State jurisdiction | Prior Two Tax Years
Subsequent Event [Line Items]
Operating loss carryforwards		3.0	$ 3.0
State jurisdiction | Future Tax Years
Subsequent Event [Line Items]
Operating loss carryforwards		3.3	3.3
Internal Revenue Service (IRS) | Domestic tax authority
Subsequent Event [Line Items]
Operating loss carryforwards generated during the period		$ 25.0	71.6
Internal Revenue Service (IRS) | Domestic tax authority | Tax Year 2015
Subsequent Event [Line Items]
Federal income taxes				$ 8.6
Internal Revenue Service (IRS) | Domestic tax authority | Prior Two Tax Years
Subsequent Event [Line Items]
Operating loss carryforwards generated during the period			49.0
Internal Revenue Service (IRS) | Domestic tax authority | Future Tax Years
Subsequent Event [Line Items]
Operating loss carryforwards generated during the period			$ 22.6
Subsequent Event
Subsequent Event [Line Items]
Payments of common stock dividends	$ 18.9
Payments of preferred dividends	0.9
Subsequent Event | Internal Revenue Service (IRS) | Domestic tax authority
Subsequent Event [Line Items]
NOL carryforward - recorded as contribution to additional paid in capital	7.9
Subsequent Event | Liberty | Parent
Subsequent Event [Line Items]
Repayments of note payable	28.7
Income taxes paid	1.3
Taxes amounts due for tax benefits	8.5
Proceeds from contributed capital	6.0
Subsequent Event | Liberty | Parent | Internal Revenue Service (IRS) | Domestic tax authority | Tax Year 2014
Subsequent Event [Line Items]
Payments to Parent for income taxes	8.5
Revolving Credit Facility | Subsequent Event | Credit Agreement, June 2016
Subsequent Event [Line Items]
Borrowing under credit agreement	$ 50.0