Earnings per Share ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator
Net income	$ 50,025	$ 81,241	$ 72,815	$ 55,726
Less net income attributable to noncontrolling interests	3,654	7,213	2,886	7,455
Net income attributable to the Company	46,371	74,028	69,929	48,271
Allocation of earnings to participating securities	(297)	(278)	(869)	(824)
Numerator for basic and diluted EPS—net income attributable to common stockholders	$ 46,074	$ 73,750	$ 69,060	$ 47,447
Denominator
Denominator for basic EPS—weighted average number of common shares outstanding (in shares)	141,368,000	141,196,000	141,325,000	141,120,000
Effect of dilutive securities:
Share and unit-based compensation plans (in share)	0	0	0	5,000
Denominator for diluted EPS—weighted average number of common shares outstanding (in shares)	141,368,000	141,196,000	141,325,000	141,125,000
EPS—net income attributable to common stockholders:
Basic (in dollars per share)	$ 0.33	$ 0.52	$ 0.49	$ 0.34
Diluted (in dollars per share)	$ 0.33	$ 0.52	$ 0.49	$ 0.34
Convertible non-participating preferred units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from Diluted EPS (in shares)	90,619	90,619	90,619	90,619
Partnership unit
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from Diluted EPS (in shares)	10,415,238	10,377,936	10,415,234	10,355,946