Summary of Significant Accounting Policies (Details) ft² in Millions, $ in Billions	Sep. 30, 2019 USD ($) ft² state property
Business Overview:
Gross investment amount, total | $	$ 4.2
Number of real estate properties | property	204
Number of states that the Company owns real estate in, whole units | state	26
Square footage of owned real estate properties	15.4
Approximate square feet for which Nationwide property management services provided by company	11.2