SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Accretion of Discount and Other Amortization (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Accretion of discount and other amortization:
Accretion of servicer advance interest income	$ 190,206		$ 4,421		$ 0
Accretion of excess mortgage servicing rights income	49,180		40,921		27,496
Accretion of net discount on securities and loans	47,793	[1]	14,676	[1]	5,339	[1]
Amortization of deferred financing costs	(8,771)		(768)		0
Accretion and other amortization	$ 278,408		$ 59,250		$ 32,835

[1] Includes accretion of the accretable yield on PCI loans.