Wexpro Agreement (Tables)

12 Months Ended

Dec. 31, 2011

Notes to Financial Statements [Abstract]

Net investment base and yearly average rate of return

Wexpro's net investment base and the yearly average rate of return are shown in the table below:

	2011			2010			2009
Wexpro's net investment base at December 31, (in millions)	$	474.4		$	456.6		$	431.9
Average annual rate of return (after tax)	20.0		%	20.0		%	20.1		%