Stockholders' Equity of the Company (Tables)

3 Months Ended

Mar. 31, 2015

Class of Stock [Line Items]

Schedule of Stockholders Equity [Table Text Block]

The following table sets forth information regarding sales of our common stock under our at-the-market offering program for the three months ended March 31, 2015:

	Three months  ended March 31, 2015
	(in millions, except share and per share data)
Shares of common stock sold during the three month period	1,507,393
Weighted average price per common share	$	76.09
Aggregate gross proceeds	$	114.7
Aggregate net proceeds after sales agent compensation	$	113.2