Incentive Compensation - Summary of Incentive Compensation Expense (Details) - 2015 LTIP - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cash—long-term incentive plan	$ 1,412	$ 2,725	$ 15,064
Total incentive compensation expense	34,457	36,663	33,064
Restricted common and subordinated units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	13,476	13,408	10,137
Restricted Performance Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	17,367	18,518	4,743
Board of Directors | Common Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total incentive compensation expense	$ 2,202	$ 2,012	$ 3,120