Fair Value Measurements And Derivative Instruments (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Mar. 31, 2014 Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member]
Derivatives, Fair Value [Line Items]
Unrealized gain (loss) recognized in accumulated other comprehensive income	$ (100)	$ 156
Unrealized gain (loss) reclassified from accumulated other comprehensive income to interest expense		356
Gain (loss) to be reclassified to interest expense during next 12 months	1,409
Carrying value and estimated fair value of debt			$ 814,702	$ 819,336	$ 812,186	$ 828,974