Indebtedness Indebtedness (Schedule of Maturities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term Debt, Current Maturities	$ 357,037
2017	350,295
2018	293,379
2019	725,912
2020	134,041
Thereafter	1,480,252
Long-term Debt	3,340,916
Interest Paid, Net	211,800	$ 229,000	$ 254,200
Interest Paid, Capitalized	$ 16,800	$ 17,600	$ 16,800