Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
BASIC
Income (loss) from continuing operations attributable to common shareholders	$ (26,653)	$ (7,629)	$ 68,310	$ 70,189
Income from discontinued operations attributable to common shareholders	0	0	0	1,682
Net income (loss) attributable to common shareholders	$ (26,653)	$ (7,629)	$ 68,310	$ 71,871
Weighted-average number of common shares outstanding - basic	234,207,396	234,018,062	233,151,600	233,457,400
Income (loss) per common share:
Income (loss) from continuing operations (in dollars per share)	$ (0.11)	$ (0.03)	$ 0.29	$ 0.30
Income (loss) from discontinued operations (in dollars per share)	0.00	0.00	0.00	0.01
Net income (loss) attributable to common shareholders (in dollars per share)	$ (0.11)	$ (0.03)	$ 0.29	$ 0.31
DILUTED
Income (loss) from continuing operations attributable to common shareholders	$ (26,653)	$ (7,629)	$ 68,310	$ 70,189
Impact of assumed conversions	0	0	(1,083)	0
Income (loss) from continuing operations attributable to common shareholders	(26,653)	(7,629)	67,227	70,189
Income from discontinued operations attributable to common shareholders	0	0	0	1,682
Impact of assumed conversions	0	0	0	0
Income from discontinued operations attributable to common shareholders	0	0	0	1,682
Net income (loss) attributable to common shareholders	$ (26,653)	$ (7,629)	$ 67,227	$ 71,871
Effect of dilutive securities:
Share options (in shares)	0	0	246,166	319,438
OP Units (in shares)	0	0	3,818,117	0
Weighted-average common shares outstanding (in shares)	234,207,396	234,018,062	237,215,883	233,776,838
Income (loss) per common share:
Income from continuing operations (in dollars per share)	$ (0.11)	$ (0.03)	$ 0.28	$ 0.30
Income (loss) from discontinued operations (in dollars per share)	0.00	0.00	0.00	0.01
Net income (loss) attributable to common shareholders (in dollars per share)	$ (0.11)	$ (0.03)	$ 0.28	$ 0.31