Consolidated Statements Of Changes In Stockholder's Equity (USD $) In Thousands, except Share data	Common Stock [Member]	Additional Paid-In Capital [Member] USD ($)	Accumulated Other Comprehensive Income (Loss), Net Of Deferred Income Taxes [Member] USD ($)	Retained Earnings [Member] USD ($)	Total USD ($)
Balance, beginning of period at Jun. 30, 2013		$ 346,279	$ 94,630	$ 3,324,429
Balance, beginning of period, shares at Jun. 30, 2013	1,000
Share-based compensation plans		2,620
Net increase (decrease) during the period			(12,595)		(12,595)
Net income (loss)				243,753	243,753
Balance, end of period at Sep. 30, 2013		348,899	82,035	3,568,182	3,999,116
Balance, end of period, shares at Sep. 30, 2013	1,000
Balance, beginning of period at Dec. 31, 2012		340,223	184,867	2,953,516
Balance, beginning of period, shares at Dec. 31, 2012	1,000
Share-based compensation plans		8,676
Net increase (decrease) during the period			(102,832)		(102,832)
Net income (loss)				614,666	614,666
Balance, end of period at Sep. 30, 2013		348,899	82,035	3,568,182	3,999,116
Balance, end of period, shares at Sep. 30, 2013	1,000
Balance, beginning of period at Dec. 31, 2013		351,051	87,648	3,751,779	4,190,478
Balance, beginning of period, shares at Dec. 31, 2013	1,000				1,000
Share-based compensation plans		8,939
Net increase (decrease) during the period			8,916		8,916
Net income (loss)				344,781	344,781
Balance, end of period at Sep. 30, 2014		359,990	96,564	4,096,560	4,553,114
Balance, end of period, shares at Sep. 30, 2014	1,000				1,000
Balance, beginning of period at Jun. 30, 2014		357,537	130,128	3,996,419
Balance, beginning of period, shares at Jun. 30, 2014	1,000
Share-based compensation plans		2,453
Net increase (decrease) during the period			(33,564)		(33,564)
Net income (loss)				100,141	100,141
Balance, end of period at Sep. 30, 2014		$ 359,990	$ 96,564	$ 4,096,560	$ 4,553,114
Balance, end of period, shares at Sep. 30, 2014	1,000				1,000