Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net income attributable to common shareholders	$ 4,453	$ 16,122
Weighted average common shares outstanding - basic (in shares)	111,296	110,916
Net effect of dilutive securities:
Contingently issuable performance shares and restricted stock units (in shares)	551	461
Weighted average common shares outstanding — diluted (in shares)	111,847	111,377
Net income attributable to common shareholders - basic (in dollars per share)	$ 0.04	$ 0.15
Net income attributable to common shareholders - diluted (in dollars per share)	$ 0.04	$ 0.14