Derivatives and Hedging Activities (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Interest Rate Swap One [Member]
Summary of interest rate derivative financial instruments
Forecasted notional amount	$ 160,000
Interest rate swap, counterparty variable interest rate	3 month LIBOR	[1]
Interest rate swap, fixed interest rate	3.378%	[1]
Effective date of interest rate swap agreements	Oct. 21, 2014	[2]
Maturity date of interest rate swap agreements	Oct. 21, 2021	[2]
Interest Rate Swap Two [Member]
Summary of interest rate derivative financial instruments
Forecasted notional amount	$ 100,000
Interest rate swap, counterparty variable interest rate	3 month LIBOR	[1]
Interest rate swap, fixed interest rate	2.498%	[1]
Effective date of interest rate swap agreements	Nov. 30, 2015	[2]
Maturity date of interest rate swap agreements	Nov. 30, 2022	[2]

[1] The Company pays the fixed interest rate and the counterparties pay the Company the variable interest rate.

[2] No cash will be exchanged prior to the term.