Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator:
Income from continuing operations	$ 19,859	$ 12,285	$ 58,014	$ 188,088
Net income available to common stockholders	$ 19,485	$ 12,067	$ 56,804	$ 184,907
Denominator:
Weighted average common shares - basic (in shares)	420,385	419,998	420,279	414,123
Earnings per common share - basic (in usd per share)	$ 0.05	$ 0.03	$ 0.14	$ 0.45
Numerator:
Income from continuing operations	$ 19,859	$ 12,285	$ 58,014	$ 188,088
Net income available to common stockholders before net income attributable to noncontrolling interests in CPLP	$ 19,811	$ 12,280	$ 57,827	$ 188,077
Denominator:
Weighted average common shares - basic (in shares)	420,385	419,998	420,279	414,123
Add:
Potential dilutive common shares - stock options (in shares)	161	328	219	320
Weighted average units of CPLP convertible into common shares (in shares)	6,974	6,974	6,974	7,511
Weighted average common shares - diluted (in shares)	427,520	427,300	427,472	421,954
Earnings per common share - diluted (in usd per share)	$ 0.05	$ 0.03	$ 0.14	$ 0.45
Stock Option
Add:
Weighted average anti-dilutive stock options outstanding (in shares)	0	731	8	740
CPLP
Numerator:
Net income attributable to other noncontrolling interests from continuing operations	$ (326)	$ (213)	$ (1,023)	$ (3,170)
Numerator:
Net income attributable to other noncontrolling interests from continuing operations	(326)	(213)	(1,023)	(3,170)
Other Noncontrolling Interests
Numerator:
Net income attributable to other noncontrolling interests from continuing operations	(48)	(5)	(187)	(11)
Numerator:
Net income attributable to other noncontrolling interests from continuing operations	$ (48)	$ (5)	$ (187)	$ (11)