Noncontrolling Interest (Details) $ in Thousands	1 Months Ended	3 Months Ended
Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Noncontrolling Interest [Line Items]
Purchase of noncontrolling interest	$ 8,700	$ 8,659
Total Transportation Of Mississippi [Member]
Noncontrolling Interest [Line Items]
Ownership in noncontrolling interest (as a percent)	10.00%	10.00%
Additional Paid-in Capital [Member]
Noncontrolling Interest [Line Items]
Purchase of noncontrolling interest	$ 5,200	$ 5,187
Noncontrolling Interest [Member]
Noncontrolling Interest [Line Items]
Purchase of noncontrolling interest	$ 3,500	$ 3,472

Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569655-111683

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 24
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4616395-111683

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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