Net Income per Unit (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended		9 Months Ended
	Aug. 15, 2016	May 16, 2016	Feb. 16, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share Basic [Line Items]
Net income and comprehensive income				$ 44,551	$ 34,711	$ 178,697	$ 177,551
Less: Net income and comprehensive income attributable to noncontrolling interest				0	852	0	2,545
Less: Preacquisition income allocated to general partner				0	6,315	0	117,728
Net income and comprehensive income attributable to partners				44,551	27,544	178,697	57,278
Less: Incentive distribution rights	$ 20,348	$ 19,566	$ 16,532	20,396	8,441	60,311	13,252
Less: Distributions on nonvested phantom unit awards				906	349	2,760	971
Limited partners’ interest in net income					18,754		43,055
Common Units [Member]
Earnings Per Share Basic [Line Items]
Limited partners’ interest in net income				$ 23,249	$ 15,004	$ 115,626	$ 31,823
Weighted average limited partner units outstanding:
Common - basic (in shares)				95,339,786	43,772,026	92,720,563	30,994,016
Common - equivalents (in shares)				74,658	116	74,658	116
Common - diluted (in shares)				95,414,444	43,772,142	92,795,221	30,994,132
Net income per limited partner unit (basic and diluted) (in dollars per share)				$ 0.24	$ 0.30	$ 1.25	$ 0.96
Subordinated Units [Member]
Earnings Per Share Basic [Line Items]
Limited partners’ interest in net income				$ 0	$ 3,750	$ 0	$ 11,232
Weighted average limited partner units outstanding:
Subordinated - basic and diluted (in shares)				0	10,939,436	0	10,939,436
Net income per limited partner unit (basic and diluted) (in dollars per share)				$ 0.00	$ 0.52	$ 0.00	$ 1.21