Bradley Agreement - Deficiency Payments, Net of Reimbursements (Details) $ in Millions	6 Months Ended
Jun. 30, 2019 USD ($)
Gain Contingency [Roll Forward]
Balance as of December 31, 2018	$ 3.9
Deficiency payments made	0.0
Deficiency repayments received	(2.5)
Balance as of June 30, 2019	$ 1.4

The amount or range of possible amounts of gain that could be realized upon the resolution of a contingency.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6397426&loc=d3e17499-108355

Name:	us-gaap_GainContingencyUnrecordedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant