Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Equity-Based Compensation Plans (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 1,919	$ 1,971	$ (4,577)
Service-Based Phantom Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Phantom units awarded during the period (in units)	29,606
Weighted average grant date fair value of phantom unit (in dollars per unit)	$ 21.28
Performance-Based Phantom Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Phantom units awarded during the period (in units)	0
Weighted average grant date fair value of phantom unit (in dollars per unit)	$ 0
2010 Plan \| Phantom Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Phantom units awarded during the period (in units)	29,606	28,484	297,214
Weighted average grant date fair value of phantom unit (in dollars per unit)	$ 21.28	$ 22.12	$ 32.37
Unrecognized compensation cost	$ 200
Weighted average period of recognition, years	3 months 18 days
Compensation expense	$ 1,800	$ 2,100
Liability for compensation awards	$ 2,800	$ 3,300
2010 Plan \| Service-Based Phantom Units \| Anniversary Year 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%
2010 Plan \| Service-Based Phantom Units \| Anniversary Year 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%
2010 Plan \| Service-Based Phantom Units \| Anniversary Year 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%
2010 Plan \| Performance-Based Phantom Units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			0.00%
2010 Plan \| Performance-Based Phantom Units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			150.00%
2010 Plan \| Performance-Based Phantom Units \| Anniversary Year 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%
2010 Plan \| Performance-Based Phantom Units \| Anniversary Year 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%
2010 Plan \| Performance-Based Phantom Units \| Anniversary Year 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%