Consolidated Statements Of Equity - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Paid-In Capital [Member]	Accumulated Earnings (Deficit) [Member]	Total PS Business Parks, Inc.'s Shareholders' Equity [Member]	Noncontrolling Interests [Member]	Total
Balances at Dec. 31, 2014	$ 995,000	$ 268	$ 709,008	$ 9,005	$ 1,713,281	$ 194,928	$ 1,908,209
Balances, shares at Dec. 31, 2014	39,800	26,919,161
Redemption of preferred stock, net of issuance costs	$ (75,000)		2,487	(2,487)	(75,000)		(75,000)
Redemption of preferred stock, net of issuance costs, shares	(3,000)
Issuance of common stock in connection with stock-based compensation		$ 1	5,088		5,089		5,089
Issuance of common stock in connection with stock-based compensation, shares		114,912
Stock compensation, net			8,178		8,178		8,178
Cash paid for taxes in lieu of shares upon vesting of restricted stock units							(767)
Net income							148,970
Net income allocable to PS Business Parks, Inc				130,475	130,475		130,475
Net income Allocation to noncontrolling interests						18,495	18,495
Distributions:
Preferred stock				(59,398)	(59,398)		(59,398)
Common stock				(59,377)	(59,377)		(59,377)
Noncontrolling interests						(16,072)	(16,072)
Adjustment to noncontrolling interests in the OP			(2,752)		(2,752)	2,752
Balances at Dec. 31, 2015	$ 920,000	$ 269	722,009	18,218	1,660,496	200,103	1,860,599
Balances, shares at Dec. 31, 2015	36,800	27,034,073
Cumulative effect of a change in accounting principle (Note 11)			807	(807)
Issuance of preferred stock, net of issuance costs	$ 189,750		(6,434)		183,316		183,316
Issuance of preferred stock, net of issuance costs, shares	7,590
Redemption of preferred stock, net of issuance costs	$ (230,000)		7,312	(7,312)	(230,000)		(230,000)
Redemption of preferred stock, net of issuance costs, shares	(9,200)
Issuance of common stock in connection with stock-based compensation		$ 2	3,886		3,888		3,888
Issuance of common stock in connection with stock-based compensation, shares		104,065
Stock compensation, net			8,404		8,404		8,404
Cash paid for taxes in lieu of shares upon vesting of restricted stock units							(1,940)
Net income							144,984
Net income allocable to PS Business Parks, Inc				128,029	128,029		128,029
Net income Allocation to noncontrolling interests						16,955	16,955
Distributions:
Preferred stock				(57,276)	(57,276)		(57,276)
Common stock				(81,285)	(81,285)		(81,285)
Noncontrolling interests						(21,916)	(21,916)
Adjustment to noncontrolling interests in the OP			(2,313)		(2,313)	2,313
Balances at Dec. 31, 2016	$ 879,750	$ 271	733,671	(433)	1,613,259	197,455	1,810,714
Balances, shares at Dec. 31, 2016	35,190	27,138,138
Issuance of preferred stock, net of issuance costs	$ 430,000		(14,221)		415,779		415,779
Issuance of preferred stock, net of issuance costs, shares	17,200
Redemption of preferred stock, net of issuance costs	$ (350,000)		10,978	(10,978)	(350,000)		(350,000)
Redemption of preferred stock, net of issuance costs, shares	(14,000)
Issuance of common stock in connection with stock-based compensation		$ 1	4,217		4,218		4,218
Issuance of common stock in connection with stock-based compensation, shares		116,469
Stock compensation, net			4,016		4,016		4,016
Cash paid for taxes in lieu of shares upon vesting of restricted stock units			(3,865)		(3,865)		(3,865)
Net income				155,037	155,037	24,279	179,316
Net income allocable to PS Business Parks, Inc							155,037
Net income Allocation to noncontrolling interests							24,279
Distributions:
Preferred stock				(52,873)	(52,873)		(52,873)
Common stock				(92,531)	(92,531)		(92,531)
Noncontrolling interests						(24,838)	(24,838)
Adjustment to noncontrolling interests in the OP			271		271	(271)
Balances at Dec. 31, 2017	$ 959,750	$ 272	$ 735,067	$ (1,778)	$ 1,693,311	$ 196,625	$ 1,889,936
Balances, shares at Dec. 31, 2017	38,390	27,254,607