Earnings Per Share Components of Earnings Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares	305,000	306,000	308,000	361,000
Weighted-average common shares outstanding - basic	88,902,000	80,745,000	88,867,000	79,515,000
Dilutive effect of potential common shares	0	0	0	0
Weighted-average common shares outstanding - diluted	88,902,000	80,745,000	88,867,000	79,515,000