Noncontrolling Interests - Holders of Convertible Limited Partnership Units in the Operating Partnership (Details) - Noncontrolling Interests shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 shares	Sep. 30, 2018 shares	Sep. 30, 2019 shares	Sep. 30, 2018 shares
Noncontrolling Interest [Line Items]
Percentage of ownership interest of noncontrolling interest	25.50%		25.50%
Limited partnership units (in shares)	7,900		7,900
Limited partnership units, conversion ratio	1		1
Outstanding stock percent that should be acquired for rights to be exercised	39.90%		39.90%
Limited partnership units convertible into shares of common stock, eligible for conversion (in shares)	2,130		2,130
Fully converted partnership units and diluted weighted average shares outstanding (in shares)	31,000	30,300	30,800	30,000