Other Fair Value Information (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term borrowings	$ 310,659	$ 12,000
Long-term debt	7,407,594	8,527,929
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes and loans receivable	488,690	213,174
Short-term borrowings	310,659	12,000
Long-term debt	7,407,594	8,527,929
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes and loans receivable	490,208	217,171
Short-term borrowings	310,659	12,000
Long-term debt	$ 7,299,405	$ 8,806,700