Share and Unit-based Plans - Schedule of LTIP Grants (Details) - $ / shares						12 Months Ended
	Jun. 01, 2017	Mar. 03, 2017	Jan. 01, 2017	Mar. 04, 2016	Jan. 01, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
LTIP units
Share and unit-based plans
Granted (shares)						569,136	506,906	480,371
Granted (in dollars per share)						$ 51.78	$ 55.33	$ 65.00
Service-based
Share and unit-based plans
Granted (shares)						569,136.000	506,906	480,371
January 1, 2016 | Service-based | First vesting period
Share and unit-based plans
Granted (shares)					58,786
Granted (in dollars per share)					$ 80.69
January 1, 2016 | Market-indexed | First vesting period
Share and unit-based plans
Granted (shares)					266,899
Granted (in dollars per share)					$ 53.32
March 3, 2016 | Service-based | Second vesting period
Share and unit-based plans
Granted (shares)				154,686
Granted (in dollars per share)				$ 79.20
January 1, 2017 | Service-based | First vesting period
Share and unit-based plans
Granted (shares)			66,079
Granted (in dollars per share)			$ 70.84
January 1, 2017 | Market-indexed | First vesting period
Share and unit-based plans
Granted (shares)			297,849
Granted (in dollars per share)			$ 47.15
March 3, 2017 | Service-based | Second vesting period
Share and unit-based plans
Granted (shares)		134,742
Granted (in dollars per share)		$ 66.57
June 1, 2017 | Service-based | Third vesting period
Share and unit-based plans
Granted (shares)	1,522
Granted (in dollars per share)	$ 58.31
June 1, 2017 | Market-indexed | Third vesting period
Share and unit-based plans
Granted (shares)	6,714
Granted (in dollars per share)	$ 39.66
January 1, 2018 | Service-based | First vesting period
Share and unit-based plans
Granted (shares)						65,466
Granted (in dollars per share)						$ 65.68
January 1, 2018 | Market-indexed | First vesting period
Share and unit-based plans
Granted (shares)						291,326
Granted (in dollars per share)						$ 44.28
January 29, 2018 | Service-based | First vesting period
Share and unit-based plans
Granted (shares)						1,893
Granted (in dollars per share)						$ 66.02
January 29, 2018 | Service-based | Second vesting period
Share and unit-based plans
Granted (shares)						13,632
Granted (in dollars per share)						$ 66.02
January 29, 2018 | Market-indexed | First vesting period
Share and unit-based plans
Granted (shares)						7,775
Granted (in dollars per share)						$ 48.23
March 2, 2018 | Service-based | Third vesting period
Share and unit-based plans
Granted (shares)						99,407
Granted (in dollars per share)						$ 59.04
April 26, 2018 | Service-based | Forth vesting period
Share and unit-based plans
Granted (shares)						89,637
Granted (in dollars per share)						$ 55.78