Accumulated Other Comprehensive Income Details 2 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Net Income (Loss) Attributable to Parent	$ 52,544	$ 52,327	$ 290,847
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(17,115)	20,791	(10,523)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 35,429	$ 73,118