UNSECURED BORROWINGS - Schedule of Subordinated Note Balances and Related Weighted Average Interest Rate (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Debt Instrument [Line Items]
Borrowings Outstanding	$ 100,000		$ 103,095
Junior subordinated notes, remaining maturity	20 years
For Final 20 Years [Member]
Debt Instrument [Line Items]
Effective borrowing rate considering cash flow hedges	7.56%
Capstead Mortgage Trust I [Member]
Debt Instrument [Line Items]
Borrowings Outstanding	35,000		36,083
Average Rate (in hundredths)	8.31%	[1]	8.31%	[1]
Capstead Mortgage Trust II [Member]
Debt Instrument [Line Items]
Borrowings Outstanding	40,000		41,238
Average Rate (in hundredths)	8.46%	[1]	8.46%	[1]
Capstead Mortgage Trust III [Member]
Debt Instrument [Line Items]
Borrowings Outstanding	25,000		25,774
Average Rate (in hundredths)	8.78%	[1]	8.78%	[1]
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Borrowings Outstanding	$ 100,000		$ 103,095
Average Rate (in hundredths)	8.49%	[1]	8.49%	[1]

[1] The indicated weighted average rates have been in effect since issuance. After considering cash flow hedges that coincide with the floating rate terms of these borrowings that begin in October and December 2015 for the notes associated with Capstead Mortgage Trusts I and II and September 2016 for the notes associated with Capstead Mortgage Trust III, the effective borrowing rate during the final 20 years of these borrowings will average 7.56%, subject to certain adjustments for the effects of measured hedge ineffectiveness, if any.