Investment In Hotel Properties (Narrative) (Details) $ in Thousands		1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 02, 2017 USD ($)	Jan. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) property shares	Dec. 31, 2016 USD ($) property shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2017 USD ($)	Feb. 21, 2017 USD ($)	Feb. 03, 2016 USD ($)
Business Acquisition [Line Items]
Depreciation expense				$ 74,288	$ 73,672	$ 68,418
Acquisition costs				2,560	1,119
Total Purchase Price				384,684	139,511
Assumption of Debt			$ 55,350	55,350	28,902
Proceeds from Contribution of Hotel Property Assets to Unconsolidated Joint Venture				429,221
Investment in hotel properties			$ 1,767,570	1,767,570	1,831,119
Reduction of consolidated mortgage debt				210,379	184,356	$ 61,348
Reduction to line of credit and unsecured term loan balance				27,000	(27,000)
Repayments of Unsecured Debt				$ 39,480
Cindat Capital Management Limited [Member] | Cindat Hersha Owner JV, LLC [Member]
Business Acquisition [Line Items]
Preferred Joint Venture Partner, Ownership Percentage				70.00%
Cash contribution by Cindat				$ 354,550
Working capital and closing costs				$ 14,105
Hersha Hospitality Limited Partnership [Member] | Cindat Hersha Owner JV, LLC [Member]
Business Acquisition [Line Items]
Percent owned (in hundredths)			30.00%	30.00%
Proceeds from Contribution of Hotel Property Assets to Unconsolidated Joint Venture				$ 354,550
Preferred equity interest			$ 43,194	43,194					$ 104,248
Working capital and closing costs				12,239
Contribution Of Closing Costs				10,653
Reduction of consolidated mortgage debt				55,103
Reduction to line of credit and unsecured term loan balance				194,550
Repayments of Unsecured Debt				$ 39,480
Limited Service Hotels In Manhattan (The "JV Properties") [Member] | Cindat Hersha Owner JV, LLC [Member]
Business Acquisition [Line Items]
Number of Real Estate Properties | property			7	7
Sale Agreement, Total Purchase Price			$ 543,500	$ 543,500
Limited Service Hotels In Manhattan (The "JV Properties") [Member] | Hersha Hospitality Limited Partnership [Member] | Cindat Hersha Owner JV, LLC [Member]
Business Acquisition [Line Items]
Approximate gain (loss) on sale				89,892
Preferred equity interest			37,000	37,000
Investment in hotel properties									$ 264,658
Additional deferred gain			81,314	81,314
Courtyard Miami Beach Lease Buyout [Member]
Business Acquisition [Line Items]
Business acquisition, cash paid			$ 5,000
Stock Issued During Period, Shares, Acquisitions | shares			225,000
Stock Issued During Period, Value, Acquisitions			$ 4,400
Write-off of an intangible liability related to the lease				2,000
Courtyard Miami Beach Lease Buyout [Member] | Scenario Plan [Member]
Business Acquisition [Line Items]
Business acquisition, cash paid				$ 10,000
Stock Issued During Period, Shares, Acquisitions | shares				450,000
Total Purchase Price				$ 18,831
Residence Inn Framingham, MA and Residence Inn, Norwood, MA [Member]
Business Acquisition [Line Items]
Total sales price			47,000	47,000
Approximate gain (loss) on sale				21,023
Hawthorn Suites Franklin, MA [Member]
Business Acquisition [Line Items]
Total sales price			8,900	8,900
Approximate gain (loss) on sale				(437)
Hyatt Place, King of Prussia, PA [Member]
Business Acquisition [Line Items]
Total sales price			13,000	13,000
Approximate gain (loss) on sale				5,402
Aquisitions In 2016 [Member]
Business Acquisition [Line Items]
Revenue				30,991
Net Income (Loss)				5,638
Aquisitions In 2015 [Member]
Business Acquisition [Line Items]
Revenue					7,150
Net Income (Loss)					$ 548
Residence Inn Greenbelt, MD; Courtyard Alexandria, VA; Hyatt House Scottsdale, AZ; Hyatt House Pleasant Hill, CA And Hyatt House Pleasanton, CA [Member]
Business Acquisition [Line Items]
Sale Agreement, Total Purchase Price			$ 185,000	$ 185,000
Residence Inn Greenbelt, MD; Courtyard Alexandria, VA; Hyatt House Scottsdale, AZ; Hyatt House Pleasant Hill, CA And Hyatt House Pleasanton, CA [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Sale Agreement, Total Purchase Price							$ 130,500
Sale Agreement Increase Decrease In Total Purchase Price		$ 7,500
Ritz-Carlton, Coconut Grove, FL [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Total Purchase Price	$ 36,000
Seller financing	$ 3,200
Pan Pacific, Seattle, WA [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Sale Agreement, Total Purchase Price								$ 79,000
Residence Inn Greenbelt, MD; Courtyard Alexandria, VA [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Sale Agreement, Total Purchase Price		$ 62,000