Derivative Instruments - Income statement disclosures (Details) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 6 Months Ended | ||
---|---|---|---|---|
Jun. 30, 2014
|
Jun. 30, 2013
|
Jun. 30, 2014
|
Jun. 30, 2013
|
|
Derivative Instruments, Gain (Loss) [Line Items] | ||||
Net gain on the valuation of contingent value rights | $ 0 | $ 8,620 | $ 0 | $ 33,420 |