Income Taxes - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
Jan. 31, 2019	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Land sale	$ 100.0	$ 108.4	$ 2.8
Current federal income tax liability reduction		15.3
Current federal income tax expense reduction		$ 15.3

Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to disposition of asset. Includes, but is not limited to, intra-entity transfer of asset other than inventory.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Name:	us-gaap_IncomeTaxReconciliationDispositionOfAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration