Partners' Capital, Equity and Incentive Compensation Plans (Summary of Award Activity Under 2010 Equity Incentive Plan and 2013 Equity Incentive Plan and Related Information) (Details)	9 Months Ended
	Sep. 30, 2016 $ / shares shares
2013 Equity Incentive Plan [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, Options Outstanding (in shares) | shares	867,882
Options, Granted (in shares) | shares	229,693
Options, Exercised (in shares) | shares	(29,543)
Options, Cancelled/Expired (in shares) | shares	(9,735)
Ending balance, Options Outstanding (in shares) | shares	1,058,297
Beginning balance, Weighted average exercise price options outstanding	$ 27.80
Weighted average exercise price options outstanding, Granted	45.78
Weighted average exercise price options outstanding, Exercised	25.70
Weighted average exercise price options outstanding, Cancelled/Expired	32.14
Ending balance, Weighted average exercise price options outstanding	31.72
Beginning balance, weighted average fair value, options	5.56
Weighted average fair value, granted, options	9.91
Weighted average fair value, vested, options	4.96
Weighted average fair value, cancelled/expired, options	6.95
Ending balance, weighted average fair value, options	$ 6.51
2013 Equity Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, Options Outstanding (in shares) | shares	394,908
Options, Granted (in shares) | shares	236,148
Options, Exercised (in shares) | shares	(83,139)
Options, Cancelled/Expired (in shares) | shares	(85,820)
Ending balance, Options Outstanding (in shares) | shares	462,097
Beginning balance, weighted average fair value, options	$ 33.82
Weighted average fair value, granted, options	45.25
Weighted average fair value, vested, options	33.07
Weighted average fair value, cancelled/expired, options	33.78
Ending balance, weighted average fair value, options	$ 39.81
Restricted Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units surrendered | shares	40,000
Class O Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ending balance, Number of units (in shares) | shares	100,000
Class O Units [Member] | 2010 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, Number of units (in shares) | shares	1,292,899
Number of units, Exercised | shares	(125,992)
Ending balance, Number of units (in shares) | shares	1,166,907
Beginning balance, Weighted average exercise price units	$ 23.76
Weighted average exercise price units, Exercised	21.45
Ending balance, Weighted average exercise price units	24.00
Beginning balance, Weighted average fair value	3.68
Weighted average fair value, Exercised	4.28
Ending balance, Weighted average fair value	$ 3.61
Class RS Units [Member] | 2010 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, Number of units (in shares) | shares	39,875
Number of units, Released from restriction (in shares) | shares	(39,875)
Beginning balance, Weighted average fair value	$ 22.18
Weighted average fair value, Released from restriction	$ 22.18