Equity and Distributions, Distributions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Distributions to Partners [Abstract]
Number of days after quarter end to distribute available cash		45 days
Number of Designated Units excluded from distributions				35,380,000
Forecast [Member]
Distributions to Partners [Abstract]
Quarterly increase in cash distribution per unit (in dollars per unit)	$ 0.0025
Cash Distribution [Member] | First Quarter 2015 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)				$ 0.3750
Record Date				Apr. 30, 2015
Payment Date				May 07, 2015
Cash Distribution [Member] | Second Quarter 2015 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)				$ 0.3800
Record Date				Jul. 31, 2015
Payment Date				Aug. 07, 2015
Cash Distribution [Member] | Third Quarter 2015 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)				$ 0.3850
Record Date				Oct. 30, 2015
Payment Date				Nov. 06, 2015
Cash Distribution [Member] | Fourth Quarter 2015 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)				$ 0.3900
Record Date				Jan. 29, 2016
Payment Date				Feb. 05, 2016
Cash Distribution [Member] | First Quarter 2016 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)			$ 0.3950
Record Date			Apr. 29, 2016
Payment Date			May 06, 2016
Cash Distribution [Member] | Second Quarter 2016 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)			$ 0.4000
Record Date			Jul. 29, 2016
Payment Date			Aug. 05, 2016
Cash Distribution [Member] | Third Quarter 2016 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)			$ 0.4050
Record Date			Oct. 31, 2016
Payment Date			Nov. 07, 2016
Cash Distribution [Member] | Fourth Quarter 2016 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)			$ 0.4100
Record Date			Jan. 31, 2017
Payment Date			Feb. 07, 2017
Cash Distribution [Member] | First Quarter 2017 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)		$ 0.4150
Record Date		Apr. 28, 2017
Payment Date		May 08, 2017
Cash Distribution [Member] | Second Quarter 2017 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)		$ 0.4200
Record Date		Jul. 31, 2017
Payment Date		Aug. 07, 2017
Cash Distribution [Member] | Third Quarter 2017 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)		$ 0.4225
Record Date		Oct. 31, 2017
Payment Date		Nov. 07, 2017
Cash Distribution [Member] | Fourth Quarter 2017 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)		$ 0.4250
Record Date		Jan. 31, 2018
Payment Date		Feb. 07, 2018
Cash Distribution [Member] | Forecast [Member] | First Quarter 2018 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)	0.4275
Cash Distribution [Member] | Forecast [Member] | Second Quarter 2018 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)	0.4300
Cash Distribution [Member] | Forecast [Member] | Third Quarter 2018 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)	0.4325
Cash Distribution [Member] | Forecast [Member] | Fourth Quarter 2018 Distribution [Member]
Distributions to Partners [Abstract]
Distribution Per Common Unit (in dollars per unit)	$ 0.4350