Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Capital stock, total shares authorized	850,000,000	850,000,000
Capital stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Capital stock, shares of excess common stock	238,000,000	238,000,000
Capital stock, authorized shares of preferred stock	100,000,000	100,000,000
Preferred stock stated dividend rate percentage	8.375%	8.375%
Series J 8 3/8% cumulative redeemable preferred stock, shares authorized	1,000,000	1,000,000
Series J 8 3/8% cumulative redeemable preferred stock, shares issued	796,948	796,948
Series J 8 3/8% cumulative redeemable preferred stock, shares outstanding	796,948	796,948
Preferred units, Liquidation value (in dollars)	$ 39,847	$ 39,847
Common stock held in treasury, shares	9,163,920	6,756,748
Common stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	511,990,000	511,990,000
Common stock, shares issued	320,322,774	319,823,322
Common stock, shares outstanding	320,322,774	319,823,322
Class B common stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	10,000	10,000
Common stock, shares issued	8,000	8,000
Common stock, shares outstanding	8,000	8,000
Simon Property Group, L.P.
Preferred units, units outstanding	796,948	796,948
Preferred units, Liquidation value (in dollars)	$ 39,847	$ 39,847
General Partner, units outstanding	311,166,854	313,074,574
Limited Partners, units outstanding	46,879,625	47,276,095