Other Fair Value Information (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term borrowings	$ 397,206	$ 310,659
Long-term debt	7,169,813	7,400,582
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes and loans receivable	761,206	488,690
Short-term borrowings	397,206	310,659
Long-term debt	7,076,820	7,400,582
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes and loans receivable	763,218	490,208
Short-term borrowings	397,206	310,659
Long-term debt	$ 7,144,588	$ 7,299,405