Derivative Financial Instruments Balance Sheet Location (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Designated As Hedging [Member]	Dec. 31, 2012 Designated As Hedging [Member]	Dec. 31, 2013 Not Designated As Hedging [Member]	Dec. 31, 2012 Not Designated As Hedging [Member]	Dec. 31, 2013 Interest Rate Swap [Member] Designated As Hedging [Member]	Dec. 31, 2012 Interest Rate Swap [Member] Designated As Hedging [Member]	Dec. 31, 2011 Interest Rate Swap [Member] Designated As Hedging [Member]	Dec. 31, 2013 Interest Rate Swap [Member] Not Designated As Hedging [Member]	Dec. 31, 2012 Interest Rate Swap [Member] Not Designated As Hedging [Member]	Dec. 31, 2013 September 2010 Swaps [Member] Cash Flow Hedging [Member] Forward-Starting Interest Rate Swap [Member]	Sep. 25, 2011 September 2010 Swaps [Member] Cash Flow Hedging [Member] Forward-Starting Interest Rate Swap [Member]	Feb. 28, 2011 September 2010 Swaps [Member] Cash Flow Hedging [Member] Forward-Starting Interest Rate Swap [Member]	Mar. 05, 2013 September 2010 and March 2011 Swaps [Member] Cash Flow Hedging [Member] Forward-Starting Interest Rate Swap [Member]	Oct. 30, 2011 September 2010 and March 2011 Swaps [Member] Cash Flow Hedging [Member] Forward-Starting Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Current derivative liability										$ (22,746)	$ 0
Derivative Liability	26,662	32,260					3,916	32,260	32,260						22,150
Derivative assets (liabilities), at fair value, net	(26,662)	(32,260)	(3,916)	(32,260)	(22,746)	0	(26,662)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax														7,200	26,058
Amount of hedged item												$ 600,000	$ 600,000			$ 600,000