Investment In Unconsolidated Joint Ventures (Investment In Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Sep. 27, 2018	Dec. 31, 2017
Investments in Unconsolidated Joint Ventures [Line Items]
Investment in unconsolidated joint ventures	$ 6,984	$ 4,004		$ 3,569
Hilton and IHG Branded Hotels in NYC [Member] | Cindat Hersha Owner JV, LLC [Member]
Investments in Unconsolidated Joint Ventures [Line Items]
Percent owned	31.20%
Investment in unconsolidated joint ventures	$ 0	0
Courtyard by Marriott, Boston, MA [Member] | Hiren Boston, LLC [Member]
Investments in Unconsolidated Joint Ventures [Line Items]
Percent owned	50.00%
Investment in unconsolidated joint ventures	$ 2,017	1,879
Holiday Inn Express, Boston, MA [Member] | SB Partners, LLC [Member]
Investments in Unconsolidated Joint Ventures [Line Items]
Percent owned	50.00%
Investment in unconsolidated joint ventures	$ 0	1,125
Home2 Suites, South Boston, MA [Member]
Investments in Unconsolidated Joint Ventures [Line Items]
Percent owned			50.00%
Investment in unconsolidated joint ventures			$ 1,000
Home2 Suites, South Boston, MA [Member] | SB Partners Three, LLC [Member]
Investments in Unconsolidated Joint Ventures [Line Items]
Percent owned	50.00%
Investment in unconsolidated joint ventures	$ 4,967	$ 1,000