Intangible Assets, Goodwill and Other Assets (Schedule of Other Assets) (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Deferred marine charges, net	[1]	$ 20,714	$ 24,098
Contract Liabilities	[2]	12,065	54,232
Other deferred costs (3)	[3]	13,068	15,755
Other assets, net of amortization		$ 45,847	$ 94,085

[1] See discussion of deferred charges on marine transportation assets in the Summary of Accounting Policies (Note 2)

[2] See Revenue Recognition (Note 3) for discussion on the circumstances that result in the recognition of contract assets.

[3] Includes unamortized debt issuance costs associated with our senior secured credit facility, which were $5.8 million and $7.6 million as of December 31, 2020 and December 31, 2019, respectively. (Note 10)