Tanger Inc. Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements Non-recurring (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2018
Fair Value, Inputs, Level 1, 2 and 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets	$ 10,000	$ 50,000
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets	0	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets	$ 10,000	$ 50,000