Equity-Based Awards - Schedule of Phantom Unit Awards (Details)	9 Months Ended
	Sep. 30, 2020 $ / shares shares
Affiliate Grants
Units
Nonvested at the beginning of the period (in units) | shares	1,309,556
Granted (in units) | shares	937,600
Forfeitures (in units) | shares	(223,229)
Vested (in units) | shares	(247,167)
Nonvested at the end of the period (in units) | shares	1,776,760
Weighted- Average Grant Date Fair Value (per unit)
Nonvested at the beginning of the period (in dollars per unit) | $ / shares	$ 28.88
Granted (in dollars per unit) | $ / shares	37.99
Forfeitures (in dollar per unit) | $ / shares	31.96
Vested (in dollars per unit) | $ / shares	25.47
Nonvested at the end of the period (in dollars per unit) | $ / shares	$ 33.78
Affiliate Grants | Time-Based Phantom Units
Units
Nonvested at the beginning of the period (in units) | shares	874,286
Granted (in units) | shares	550,540
Forfeitures (in units) | shares	(120,176)
Vested (in units) | shares	(193,522)
Nonvested at the end of the period (in units) | shares	1,111,128
Weighted- Average Grant Date Fair Value (per unit)
Nonvested at the beginning of the period (in dollars per unit) | $ / shares	$ 28.90
Granted (in dollars per unit) | $ / shares	37.97
Forfeitures (in dollar per unit) | $ / shares	32.97
Vested (in dollars per unit) | $ / shares	25.49
Nonvested at the end of the period (in dollars per unit) | $ / shares	$ 33.55
Affiliate Grants | Performance-Based Phantom Units
Units
Nonvested at the beginning of the period (in units) | shares	435,270
Granted (in units) | shares	387,060
Forfeitures (in units) | shares	(103,053)
Vested (in units) | shares	(53,645)
Nonvested at the end of the period (in units) | shares	665,632
Weighted- Average Grant Date Fair Value (per unit)
Nonvested at the beginning of the period (in dollars per unit) | $ / shares	$ 28.84
Granted (in dollars per unit) | $ / shares	38.02
Forfeitures (in dollar per unit) | $ / shares	30.78
Vested (in dollars per unit) | $ / shares	25.39
Nonvested at the end of the period (in dollars per unit) | $ / shares	$ 34.16
Director Grants | Time-Based Phantom Units
Units
Nonvested at the beginning of the period (in units) | shares	13,264
Granted (in units) | shares	14,987
Vested (in units) | shares	(13,264)
Nonvested at the end of the period (in units) | shares	14,987
Weighted- Average Grant Date Fair Value (per unit)
Nonvested at the beginning of the period (in dollars per unit) | $ / shares	$ 30.16
Granted (in dollars per unit) | $ / shares	38.37
Vested (in dollars per unit) | $ / shares	30.16
Nonvested at the end of the period (in dollars per unit) | $ / shares	$ 38.37