Quarterly report pursuant to Section 13 or 15(d)

Derivative Contracts (Details 2)

v2.4.0.8
Derivative Contracts (Details 2) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2014
Not Designated as Hedging Instrument [Member]
Jun. 30, 2013
Not Designated as Hedging Instrument [Member]
Jun. 30, 2014
Not Designated as Hedging Instrument [Member]
Jun. 30, 2013
Not Designated as Hedging Instrument [Member]
Jun. 30, 2014
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
Jun. 30, 2013
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
Jun. 30, 2014
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
Jun. 30, 2013
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
Dec. 31, 2013
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
Jun. 30, 2014
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
0 to 30 [Member]
Dec. 31, 2013
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
0 to 30 [Member]
Jun. 30, 2014
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
31 to 60 [Member]
Dec. 31, 2013
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
31 to 60 [Member]
Jun. 30, 2014
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
61 to 90 [Member]
Dec. 31, 2013
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
61 to 90 [Member]
Jun. 30, 2014
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
91 to 120 [Member]
Dec. 31, 2013
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
91 to 120 [Member]
Jun. 30, 2014
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
121 to 180 [Member]
Dec. 31, 2013
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
121 to 180 [Member]
Dec. 31, 2013
Not Designated as Hedging Instrument [Member]
Forward Contracts [Member]
More than 180 [Member]
Jun. 30, 2014
Notes Due February 1, 2033
2033 Senior Notes
Dec. 31, 2013
Notes Due February 1, 2033
2033 Senior Notes
Jan. 31, 2013
Notes Due February 1, 2033
2033 Senior Notes
Derivative [Line Items]                                              
Interest rate of notes payable                                         3.00% 3.00% 3.00%
Contract value         $ 3,679   $ 3,679   $ 1,537 $ 1,157 $ 472 $ 966 $ 562 $ 623 $ 503 $ 831 $ 0 $ 102 $ 0 $ 0      
Fair value         3,624   3,624   1,585 1,146 489 951 579 612 517 815 0 100 0         
Derivative, Gain (Loss) on Derivative, Net $ 10,967 $ 12,651 $ 452 $ (10,898) $ (55) $ 154 $ (55) $ 133 $ 49 $ (11) $ 17 $ (15) $ 18 $ (11) $ 14 $ (16) $ 0 $ (2) $ 0 $ 0      
Contract days until maturity, lower range                   0 days 0 days 31 days 31 days 61 days 61 days 91 days 91 days 121 days 121 days        
Contract days until maturity, higher range                   30 days 30 days 60 days 60 days 90 days 90 days 120 days 120 days 180 days 180 days 180 days