Derivative Instruments (Table Text Block)

3 Months Ended

Jun. 30, 2012

Derivative Instrument Detail [Abstract]

Schedule of derivative instruments

We manage exposure to changes in market interest rates. Our use of derivative instruments is limited to highly effective interest rate swaps to hedge the risk of changes in cash flows (future interest payments) attributable to changes in LIBOR swap rates, the designated benchmark interest rate being hedged on certain of our LIBOR indexed variable rate debt and a variable rate operating lease. The interest rate swaps effectively fix our interest payments on certain LIBOR indexed variable rate debt. We monitor our positions and the credit ratings of our counterparties and do not currently anticipate non-performance by the counterparties. Interest rate swap agreements are not entered into for trading purposes.

Original variable rate debt and lease amount			Agreement Date	Effective Date	Expiration Date	Designated cash flow hedge date
(In millions)
$	50.0		6/21/2006	7/10/2006	7/10/2013	6/9/2006
	144.9	(a)	6/9/2006	10/10/2006	10/10/2012	6/9/2006
	300.0		8/16/2006	8/18/2006	8/10/2018	8/4/2006
	30.0		2/9/2007	2/12/2007	2/10/2014	2/9/2007
	20.0		3/8/2007	3/12/2007	3/10/2014	3/8/2007
	20.0		3/8/2007	3/12/2007	3/10/2014	3/8/2007
	19.3	(a)	4/8/2008	8/15/2008	6/15/2015	3/31/2008
	19.0		8/27/2008	8/29/2008	7/10/2015	4/10/2008
	30.0		9/24/2008	9/30/2008	9/10/2015	9/24/2008
	15.0	(a)	3/24/2009	3/30/2009	3/30/2016	3/25/2009
	14.7	(a)	7/6/2010	8/15/2010	7/15/2017	7/6/2010
	25.0	(a)	4/26/2011	6/1/2011	6/1/2018	6/1/2011
	50.0	(a)	7/29/2011	8/15/2011	8/15/2018	7/29/2011
	20.0	(a)	8/3/2011	9/12/2011	9/10/2018	8/3/2011
	15.1	(b)	3/27/2012	3/28/2012	3/28/2019	3/26/2012
	25.0		4/13/2012	4/16/2012	4/1/2019	4/12/2012
(a) forward swap
(b) operating lease

As of June 30, 2012, the total notional amount of our variable interest rate swaps on debt and an operating lease was $480.5 million and $14.8 million, respectively.