Long-Term Debt (Schedule of Required Future Principal Payments on Term Loans) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Long-term Debt, Fiscal Year Maturity
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 89,911
Long-term Debt, Maturities, Repayments of Principal in Year Two	666,303
Long-term Debt, Maturities, Repayments of Principal in Year Three	151,566
Long-term Debt, Maturities, Repayments of Principal in Year Four	488,645
Long-term Debt, Maturities, Repayments of Principal in Year Five	3,287,628
Long-term Debt, Maturities, Repayments of Principal after Year Five	4,834,423
Total maturities	9,518,476
Term Loans [Member]
Long-term Debt, Fiscal Year Maturity
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	75,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	358,528
Long-term Debt, Maturities, Repayments of Principal in Year Three	147,336
Long-term Debt, Maturities, Repayments of Principal in Year Four	484,836
Long-term Debt, Maturities, Repayments of Principal in Year Five	3,265,862
Total maturities	$ 4,331,562