Organization and Basis of Presentation - Accumulated Other Comprehensive Loss - Partnership (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	$ 6,337,023
Balance at period end	6,215,076
Essex Portfolio, L.P. [Member] | AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	(39,598)
Other comprehensive (loss) income before reclassification	(3,318)
Amounts reclassified from accumulated other comprehensive loss	2,288
Other comprehensive (loss) income	(1,030)
Balance at period end	(40,628)
Essex Portfolio, L.P. [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	(46,087)
Other comprehensive (loss) income before reclassification	(5,466)
Amounts reclassified from accumulated other comprehensive loss	4,131
Other comprehensive (loss) income	(1,335)
Balance at period end	(47,422)
Essex Portfolio, L.P. [Member] | Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at period beginning	6,489
Other comprehensive (loss) income before reclassification	2,148
Amounts reclassified from accumulated other comprehensive loss	(1,843)
Other comprehensive (loss) income	305
Balance at period end	$ 6,794