Derivatives (Tables)

3 Months Ended

Mar. 31, 2016

Derivative [Line Items]

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

The table below summarizes information about the Company’s derivative instruments treated as trading instruments on its consolidated balance sheet as of the dates indicated:  

	March 31, 2016
	Derivative Assets				Derivative Liabilities
Trading Instruments	Fair Value		Notional		Fair Value			Notional
Interest rate swaps	$	14,845	$	425,000	$	(49,204	)	$	1,705,000
Eurodollar futures (1)	—		—		(41,283		)	6,300,000
Total	$	14,845	$	425,000	$	(90,487	)	$	8,005,000

	December 31, 2015
	Derivative Assets				Derivative Liabilities
Trading Instruments	Fair Value		Notional		Fair Value			Notional
Interest rate swaps	$	7,835	$	460,000	$	(12,108	)	$	2,920,000
Eurodollar futures (1)	—		—		(29,097		)	6,300,000
Total	$	7,835	$	460,000	$	(41,205	)	$	9,220,000

(1) The Eurodollar futures aggregate notional amount represents the total notional of the 3-month contracts with expiration dates from 2017 to 2020. The maximum notional outstanding for any future 3-month period did not exceed $725,000 as of March 31, 2016 or as of December 31, 2015.

Schedule of Derivative Instruments [Table Text Block]

The following table summarizes the contractual maturities remaining for the Company’s outstanding interest rate swap agreements as of March 31, 2016:

Remaining Maturity	Pay-Fixed Interest Rate Swaps		Pay-Fixed Weighted-Average Rate		Receive-Fixed Interest Rate Swaps		Receive-Fixed Weighted-Average Rate
13-24 months	$	185,000	0.92	%	$	—	—	%
25-36 months	125,000		1.40	%	—		—	%
37-48 months	470,000		1.74	%	250,000		1.91	%
49-60 months	250,000		1.58	%	150,000		1.71	%
61-72 months	75,000		1.77	%	—		—	%
73-84 months	125,000		1.98	%	—		—	%
85-96 months	—		—	%	—		—	%
97-108 months	—		—	%	25,000		2.71	%
109-120 months	475,000		2.86	%	—		—	%

Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]

The following table summarizes the volume of activity related to derivative instruments for the period indicated:

For the three months ended March 31, 2016:	Beginning of Period Notional Amount		Additions		Settlement, Termination, Expiration or Exercise			End of Period Notional Amount
Receive-fixed interest rate swaps	$	425,000	$	—	$	—		$	425,000
Pay-fixed interest rate swaps	2,955,000		1,000,000		(2,250,000		)	1,705,000
Eurodollar futures	6,300,000		—		—			6,300,000
	$	9,680,000	$	1,000,000	$	(2,250,000	)	$	8,430,000

Schedule of Derivative Instruments Included in Trading Activities [Table Text Block]

The table below provides detail of the Company's "loss on derivative instruments, net" by type of interest rate derivative for the periods indicated:

	Three Months Ended
	March 31,
Type of Derivative Instrument	2016			2015
Receive-fixed interest rate swaps	$	10,534		$	4,528
Pay-fixed interest rate swaps	(46,612		)	(13,363		)
Eurodollar futures	(12,186		)	(16,488		)
Loss on derivative instruments, net	$	(48,264	)	$	(25,323	)