Organization and Summary of Significant Accounting Policies (Consolidated Statement of Cash Flows) (Details) (USD $) In Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net income	$ 40,747	$ 55,832	$ 75,700
Deferred income tax provision		5,539	(8,239)
Postretirement and pension plan		1,780	1,836
Previously Reported [Member]
Net income	39,322	55,800	72,850
Deferred income tax provision			(8,242)
Postretirement and pension plan			4,689
Revised [Member]
Net income	40,747	53,400	75,700
Deferred income tax provision			(8,239)
Postretirement and pension plan			1,836
Impact of Adjustments To Financial Statements [Member]
Net income	1,425		2,850
Deferred income tax provision			3
Postretirement and pension plan			$ (2,853)