Debt Obligations (Aggregate Scheduled Principal Payments of Debt Obligation, Excluding Amortization of Discounts and Premiums) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Extinguishment of Debt [Line Items]
2013	$ 261,996	[1]
2014	102,030
2015	367,703
2016	330,323
2017	336,954
Thereafter	1,322,454
Total principal payments	2,721,460
Net unamortized premiums/(discounts)	(8,080)
Total Debt Obligations	$ 2,713,380		$ 2,595,381

[1] (a)The Company completed the redemption of the 5.40% Guaranteed Notes due November 1, 2014 and 7.50% Guaranteed Notes due May 15, 2015 through a tender offer on October 16, 2014. See Note 17 - Subsequent Events, for discussion of redemption.