Schedule I (Parent Co Statement of Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$ 275,779	$ 230,049	$ (1,000)
Other comprehensive income, net of tax	1,522	(66,237)	41,154
Comprehensive income	277,301	163,812	40,154
Parent
Net income	275,779	210,489	(18,383)
Other comprehensive income, net of tax	1,522	(66,237)	41,154
Comprehensive income	$ 277,301	$ 144,252	$ 22,771

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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