Nature of Operations, Basis of Presentation, and Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) |
Jun. 30, 2020 |
Feb. 07, 2020 |
Dec. 31, 2019 |
---|---|---|---|
Stifel Credit Facility [Member] | |||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | |||
Credit facility | $ 300,000,000.0 | ||
North Shore Aviation Holdings LLC [Member] | |||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | |||
Noncontrolling Interest, Ownership Percentage by Parent | 27.50% | ||
North Shore Aviation Holdings LLC [Member] | Stifel Credit Facility [Member] | |||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | |||
Credit facility | $ 120,000,000.0 |