Derivative Financial Instruments - Derivative Offsetting (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Derivative
Derivative financial instruments	$ 4,418	$ 0
Derivative assets, amounts subject to enforceable master netting arrangements	(1,628)	0
Derivative assets, net amounts	2,790	0
Derivative liabilities	2,065	9,370
Derivative liabilities, amounts subject to enforceable master netting arrangements	(1,628)	0
Derivative liabilities, net amounts	$ 437	$ 9,370

Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

+ References+ Details

Fair value of derivative asset, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

+ References+ Details

- Definition

Fair value of derivative liability, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

+ References+ Details

- Definition

Fair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

+ References+ Details