Earnings Per Share (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share [Abstract]
Weighted-average common shares outstanding - basic	48,332,878	41,292,819	46,886,820	39,178,952
Dilutive effect of Equity-based Incentive Awards	0	1,565,061	908,999	1,554,861
Weighted-average common shares outstanding - diluted	48,332,878	42,857,880	47,795,819	40,733,813
Anti-dilutive Equity-based Incentive Awards excluded from the computation of diluted income per share	658,445	30,000	575,059	46,560