Derivative Financial Instruments - Summary of Eurodollar Futures Positions (Details) (Eurodollar Future [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Locked-In LIBOR Rate	2.01%	2.02%
Notional Amount	$ 390,625,000	$ 257,353,000
Open Equity	3,453,000	4,898,000
Year 2014 Expiration [Member]
Derivatives, Fair Value [Line Items]
Locked-In LIBOR Rate	0.32%	0.40%
Notional Amount	400,000,000	262,500,000
Open Equity	(211,000)	(189,000)
Year 2015 Expiration [Member]
Derivatives, Fair Value [Line Items]
Locked-In LIBOR Rate	0.78%	0.80%
Notional Amount	400,000,000	275,000,000
Open Equity	(264,000)	(146,000)
Year 2016 Expiration [Member]
Derivatives, Fair Value [Line Items]
Locked-In LIBOR Rate	1.90%	1.90%
Notional Amount	400,000,000	250,000,000
Open Equity	1,354,000	1,367,000
Year 2017 Expiration [Member]
Derivatives, Fair Value [Line Items]
Locked-In LIBOR Rate	2.85%	3.03%
Notional Amount	400,000,000	250,000,000
Open Equity	1,777,000	2,291,000
Year 2018 Expiration [Member]
Derivatives, Fair Value [Line Items]
Locked-In LIBOR Rate	3.44%	3.77%
Notional Amount	350,000,000	250,000,000
Open Equity	$ 797,000	$ 1,575,000