Derivatives and Other Financial Instruments (Summary of Interest Rate Swaps and Stock Purchase Warrants Fair Value) (Details) (USD $) In Thousands, unless otherwise specified					6 Months Ended				6 Months Ended
	Jun. 30, 2011		Dec. 31, 2010		Jun. 30, 2011 Interest Rate Swap (A) [Member]		Dec. 31, 2010 Interest Rate Swap (A) [Member]		Jun. 30, 2011 Interest Rate Swap (B) [Member]		Dec. 31, 2010 Interest Rate Swap (B) [Member]		Jun. 30, 2011 Interest Rate Swaps [Member]		Mar. 31, 2011 Interest Rate Swaps [Member]	Dec. 31, 2010 Interest Rate Swaps [Member]		Jun. 30, 2011 Interest Rate Swap (2) [Member]	Jun. 30, 2011 Other [Member]		Dec. 31, 2010 Other [Member]
Current Notional Amount	$ 150,000				$ 115,000				$ 35,000				$ 150,000		$ 150,000			$ 250,000
Strike Rate					4.673%				4.70%				5.80%
Effective Date					Oct. 01, 2007				Oct. 10, 2007
Expiration Date					Aug. 01, 2011				Aug. 01, 2011
Fair-Value	$ (558)	[1]	$ (3,800)	[1]	$ (444)	[1]	$ (2,928)	[1]	$ (136)	[1]	$ (898)	[1]	$ (580)	[1]		$ (3,826)	[1]		$ 22	[1],[2]	$ 26	[1],[2]

[1] Fair-value of derivative instruments does not include any related accrued interest payable, which is included in accrued expenses on the accompanying consolidated balance sheets. Derivative valuations are classified in Level 2 of the fair-value hierarchy.

[2] Includes stock purchase warrants that are recorded as derivative instruments and are reflected in other assets on the accompanying consolidated balance sheets. Changes in the fair-value of the stock purchase warrants are included in earnings in the period in which they occur.