Marketable Securities	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable SecuritiesAs of March 31, 2019 and December 31, 2018, we owned 535,265 common shares of The Macerich Company (“Macerich”) (NYSE: MAC). These shares have an economic cost of $56.05 per share, or $30,000,000 in the aggregate. As of March 31, 2019 and December 31, 2018, the fair value of these shares was $23,204,000 and $23,166,000, respectively, based on Macerich’s closing share price of $43.35 per share and $43.28 per share, respectively. These shares are included in “marketable securities” on our consolidated balance sheets and are classified as available-for-sale. Available-for-sale securities are presented at fair value on our consolidated balance sheets and gains and losses resulting from the mark-to-market of these securities are recognized in current period earnings.