Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Commercial real estate properties, at cost:
Land	$ 201,196	$ 201,196
Development costs	7,986	7,986
Building and improvements	2,495,901	2,458,473
Commercial real estate properties, at cost, gross	2,705,083	2,667,655
Less: accumulated depreciation	(678,250)	(656,900)
Commercial real estate properties, net	2,026,833	2,010,755
Cash and cash equivalents	690,471	464,344
Restricted cash	61,699	65,853
Tenant and other receivables, net of allowance of $1,128 and $1,422 in 2018 and 2017, respectively	25,156	28,329
Deferred rent receivables, net of allowance of $0 and $185 in 2018 and 2017, respectively	184,667	178,629
Prepaid expenses and other assets	39,393	61,028
Deferred costs, net	255,844	262,701
Acquired below-market ground leases, net	366,271	368,229
Goodwill	491,479	491,479
Total assets	4,141,813	3,931,347
Liabilities:
Mortgage notes payable, net	610,826	717,164
Senior unsecured notes, net	1,043,677	707,895
Unsecured term loan facility, net	263,777	263,662
Unsecured revolving credit facility	0	0
Accounts payable and accrued expenses	106,830	110,849
Acquired below-market leases, net	62,418	66,047
Deferred revenue and other liabilities	37,499	40,907
Tenants’ security deposits	43,448	47,086
Total liabilities	2,168,475	1,953,610
Commitments and contingencies
Empire State Realty Trust, Inc. stockholders' equity:
Preferred stock	0	0
Additional paid-in capital	1,138,600	1,128,460
Accumulated other comprehensive loss	(6,037)	(8,555)
Retained earnings	39,323	46,762
Total Empire State Realty Trust, Inc.'s stockholders' equity	1,173,529	1,168,282
Non-controlling interests in operating partnership	791,805	801,451
Private perpetual preferred units, $16.62 per unit liquidation preference, 1,560,360 issued and outstanding in 2018 and 2017	8,004	8,004
Total equity	1,973,338	1,977,737
Total liabilities and equity	4,141,813	3,931,347
Class A Common Stock
Empire State Realty Trust, Inc. stockholders' equity:
Common stock	1,633	1,604
Class B Common Stock
Empire State Realty Trust, Inc. stockholders' equity:
Common stock	$ 10	$ 11