Borrowing Arrangements (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Borrowing Arrangements
Liability to make principal payments on debt outstanding in 2014	$ 2,200,000
Liability to make principal payments on debt outstanding in 2017	5,700,000
Liability to make principal payments on debt outstanding in 2018	26,400,000
Interest Expense
Interest expense	462,000	80,000
Interest costs capitalized	$ 400,000	$ 700,000	$ 1,000,000