Derivative Instruments and Hedging Activities (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Debt Instrument, Redemption, Period One [Member] | Mortgage Loan On Headquarters Facility [Member] | Mortgages [Member]
Schedule of interest rate derivatives designated as cash flow hedges of interest rate risk
Strike rate	5.91%
Debt Instrument, Redemption, Period Two [Member] | Mortgage Loan On Headquarters Facility [Member] | Mortgages [Member]
Schedule of interest rate derivatives designated as cash flow hedges of interest rate risk
Strike rate	6.07%
Interest rate swap [Member] | First half of mortgage [Member]
Schedule of interest rate derivatives designated as cash flow hedges of interest rate risk
Notional	$ 1,653
Asset (Liability)	(139)
Effective Date	Apr. 01, 2010
Maturity Date	Apr. 01, 2019
Derivative, Type of Interest Rate Paid on Swap	1-month LIBOR
Strike rate	5.91%
Interest rate swap [Member] | Second half of mortgage [Member]
Schedule of interest rate derivatives designated as cash flow hedges of interest rate risk
Notional	1,653
Asset (Liability)	$ (150)
Effective Date	Apr. 01, 2010
Maturity Date	Apr. 01, 2019
Derivative, Type of Interest Rate Paid on Swap	1-month LIBOR
Strike rate	6.07%