Equity-Based Compensation - Performance Awards (Details) - Performance Shares - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Shares
Beginning of Period (in shares)	1,165	1,627
Granted (in shares)	506	400
Forfeited or Expired (in shares)	0	(1)
Paid Out (in shares)	(424)	(861)
End of Period (in shares)	1,247	1,165
Weighted-Average Grant Date Fair Value
Beginning of Period (in USD per share)	$ 60.45	$ 49.46
Granted (in USD per share)	50.81	72.24
Forfeited or Expired (in USD per share)	0.00	41.02
Paid Out (in USD per share)	49.27	45.09
End of Period (in USD per share)	$ 60.37	$ 60.45