Earnings Per Share Components of Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Weighted-average common shares outstanding - basic	80,745	78,183	79,515	78,154
Dilutive effect of potential common shares	0	1,868	0	1,588
Weighted-average common shares outstanding - diluted	80,745	80,051	79,515	79,742