Indebtedness - Overview (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Disclosure [Abstract]
Debt, Weighted Average Interest Rate	5.10%	5.30%	5.80%
Interest Costs, Capitalized During Period	$ 9,600,000	$ 9,919,000	$ 3,000,000
Interest Paid	$ 143,200,000	$ 132,200,000	$ 134,300,000