Commitments and Contingencies (Details)	Mar. 31, 2019 USD ($)
Loss Contingencies [Line Items]
Aggregate face amount of letter of credit agreements	$ 225,000,000
Performance Guarantee [Member]
Loss Contingencies [Line Items]
Liability for guarantees	0
Margin Requirements [Member]
Loss Contingencies [Line Items]
Funds drawn under LOC's	$ 0

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248

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