Net Income Per Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net Income Per Unit [Line Items]
Net income attributable to partners	$ 44,415	$ 24,885	$ 72,211	$ 44,581
Less: Partners' distribution	26,490	20,754	48,229	40,769
Allocation of earnings in excess (deficit) of distributions	$ 8,446	$ (4,029)	$ 5,364	$ (11,771)
Footnote [Abstract]
Common Units Excluded From Computation Of Earnings Per Unit, Units		0	18,270	0
Common Units
Net Income Per Unit [Line Items]
Common units - (basic) (in shares)	29,427,298	24,409,359	26,953,934	24,408,270
Common units - (diluted) (in shares)	29,430,555	24,414,343	26,956,523	24,414,077
Common units - (basic) (in dollars per share)	$ 1.18	$ 0.69	$ 1.98	$ 1.20
Common units - (diluted) (in dollars per share)	$ 1.18	$ 0.69	$ 1.98	$ 1.20
General Partner
Net Income Per Unit [Line Items]
Net income attributable to partners	$ 9,647	$ 8,079	$ 18,724	$ 15,349
Less: General partner's distribution (including IDRs)	9,479	8,160	18,618	15,583
Allocation of earnings in excess (deficit) of distributions	168	(81)	106	(235)
Total partner's earnings	9,647	8,079	18,724	15,348
Common unitholders
Net Income Per Unit [Line Items]
Less: Partners' distribution			48,229	40,769
Allocation of earnings in excess (deficit) of distributions			$ 5,258	$ (11,536)
Common units - (basic) (in shares)			26,953,934	24,408,270
Common units - (diluted) (in shares)			26,956,523	24,414,077
Common units - (basic) (in dollars per share)			$ 1.98	$ 1.20
Common units - (diluted) (in dollars per share)			$ 1.98	$ 1.20
Common unitholders \| Common Units
Net Income Per Unit [Line Items]
Less: Partners' distribution	26,490	20,754
Allocation of earnings in excess (deficit) of distributions	8,278	(3,948)
Total partner's earnings	$ 34,768	$ 16,806	$ 53,487	$ 29,233
Common units - (basic) (in shares)	29,427,298	24,409,359
Common units - (diluted) (in shares)	29,430,555	24,414,343
Common units - (basic) (in dollars per share)	$ 1.18	$ 0.69
Common units - (diluted) (in dollars per share)	1.18	$ 0.69
Maximum
Footnote [Abstract]
Distribution Payment Targets	$ 0.43125
General Partnership [Member]
Footnote [Abstract]
General partner's ownership interest (as percent)	2.00%	2.00%	2.00%	2.00%

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