Fair Value Measurements (Effect of Fair Value Measured Assets and Liabilities on Consolidated Statements of Operations) (Details) (USD $) | 3 Months Ended | 6 Months Ended |
In Thousands, unless otherwise specified | Jun. 30, 2014 | Jun. 30, 2013 | Jun. 30, 2014 | Jun. 30, 2013 |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Unrealized gains (losses) on derivatives | ($263) | $789 | ($610) | ($6,360) |
Unrealized gain (loss) on marketable securities | -944 | -919 | -943 | 1,782 |
Credit Default Swaps [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Unrealized gains (losses) on derivatives | -191 | 773 | -417 | -131 |
Derivative Assets [Member] | Credit Default Swaps [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | ' | ' | -459 | 0 |
Reclassified from Accumulated OCI into Interest Expense, Assets | ' | ' | 0 | 0 |
Interest Savings (Cost) [Member] | Derivative Assets [Member] | Credit Default Swaps [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | ' | ' | 0 | 0 |
Fair Value Measurements Recurring [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | 602 | -48 | 1,359 | -5,016 |
Unrealized gains (losses) on derivatives | -263 | 789 | -610 | -6,360 |
Unrealized gain (loss) on marketable securities | -944 | -919 | -943 | 1,782 |
Realized gain (loss) on marketable securities | 1,809 | 82 | 2,912 | -438 |
Gain or (Loss) Recognized in income, Net | 602 | -48 | 1,359 | -5,016 |
Reclassified from Accumulated OCI into Interest Expense, Liabilities | 29 | 16 | 100 | 24 |
Reclassified from Accumulated OCI into Interest Expense, Net | 29 | 16 | 100 | 24 |
Fair Value Measurements Recurring [Member] | Interest Rate Derivatives [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Unrealized gains (losses) on derivatives | -72 | 16 | -193 | -6,229 |
Reclassified from Accumulated OCI into Interest Expense, Net | 29 | 16 | 100 | 24 |
Fair Value Measurements Recurring [Member] | Credit Default Swaps [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Unrealized gains (losses) on derivatives | -191 | 773 | -417 | -131 |
Reclassified from Accumulated OCI into Interest Expense, Net | 0 | 0 | 0 | 0 |
Fair Value Measurements Recurring [Member] | Derivative Liabilities [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | -428 | 1,420 | ' | ' |
Reclassified from Accumulated OCI into Interest Expense, Liabilities | 0 | 0 | ' | ' |
Fair Value Measurements Recurring [Member] | Derivative Liabilities [Member] | Interest Rate Derivatives [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | ' | ' | 0 | 4,400 |
Reclassified from Accumulated OCI into Interest Expense, Liabilities | ' | ' | 0 | 0 |
Fair Value Measurements Recurring [Member] | Derivative Liabilities [Member] | Credit Default Swaps [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | ' | ' | 0 | -175 |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings | 0 | 750 | ' | ' |
Reclassified from Accumulated OCI into Interest Expense, Liabilities | 0 | 0 | 0 | 0 |
Fair Value Measurements Recurring [Member] | Derivative Liabilities [Member] | Put Option [Member] | Short [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | -368 | 0 | 23 | 7 |
Reclassified from Accumulated OCI into Interest Expense, Liabilities | 0 | 0 | 0 | 0 |
Fair Value Measurements Recurring [Member] | Derivative Liabilities [Member] | Call Option [Member] | Short [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | -60 | 670 | -56 | 85 |
Reclassified from Accumulated OCI into Interest Expense, Liabilities | 0 | 0 | 0 | 0 |
Fair Value Measurements Recurring [Member] | Non-Derivative Liabilities [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | ' | ' | -33 | 4,317 |
Reclassified from Accumulated OCI into Interest Expense, Liabilities | ' | ' | 0 | 0 |
Fair Value Measurements Recurring [Member] | Derivative Assets [Member] | Interest Rate Derivatives [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | -72 | 16 | -193 | -10,629 |
Reclassified from Accumulated OCI into Interest Expense, Assets | 29 | 16 | 100 | 24 |
Fair Value Measurements Recurring [Member] | Derivative Assets [Member] | Put and Call Options [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | -592 | -18 | -1,104 | 186 |
Reclassified from Accumulated OCI into Interest Expense, Assets | 0 | 0 | 0 | 0 |
Fair Value Measurements Recurring [Member] | Derivative Assets [Member] | Credit Default Swaps [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | -212 | 0 | ' | ' |
Reclassified from Accumulated OCI into Interest Expense, Assets | 0 | 0 | ' | ' |
Fair Value Measurements Recurring [Member] | Non Derivative Assets [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | 1,030 | -1,468 | 1,392 | -9,333 |
Reclassified from Accumulated OCI into Interest Expense, Assets | 29 | 16 | 100 | 24 |
Fair Value Measurements Recurring [Member] | Non Derivative Assets [Member] | Equity and U.S Treasury Securities [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | 1,906 | -1,466 | 3,148 | 1,110 |
Reclassified from Accumulated OCI into Interest Expense, Assets | 0 | 0 | 0 | 0 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | ' | ' | 0 | 6,215 |
Unrealized gains (losses) on derivatives | ' | ' | 0 | 6,215 |
Unrealized gain (loss) on marketable securities | ' | ' | 0 | 0 |
Realized gain (loss) on marketable securities | ' | ' | 0 | 0 |
Gain or (Loss) Recognized in income, Net | ' | ' | 0 | 6,215 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Interest Rate Derivatives [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Unrealized gains (losses) on derivatives | ' | ' | 0 | 6,215 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Credit Default Swaps [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Unrealized gains (losses) on derivatives | ' | ' | 0 | 0 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Derivative Liabilities [Member] | Interest Rate Derivatives [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | ' | ' | 0 | -4,424 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Derivative Liabilities [Member] | Credit Default Swaps [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | ' | ' | 0 | 0 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Derivative Liabilities [Member] | Put Option [Member] | Short [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | ' | ' | 0 | 0 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Derivative Liabilities [Member] | Call Option [Member] | Short [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | ' | ' | 0 | 0 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Non-Derivative Liabilities [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Liabilities | ' | ' | 0 | -4,424 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Derivative Assets [Member] | Interest Rate Derivatives [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | ' | ' | 0 | 10,639 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Derivative Assets [Member] | Put and Call Options [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | ' | ' | 0 | 0 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Non Derivative Assets [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | ' | ' | 0 | 10,639 |
Fair Value Measurements Recurring [Member] | Interest Savings (Cost) [Member] | Non Derivative Assets [Member] | Equity and U.S Treasury Securities [Member] | ' | ' | ' | ' |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ' | ' | ' | ' |
Gain or (Loss) Recognized in income, Assets | ' | ' | $0 | $0 |