Fair Value Measurements - Roll Forward, Level 3 (Details) - Level 3 - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Rollforward for financial instruments measured at fair value using Level 3 inputs
Asset balance, beginning of period	$ 78,166	$ 45,172
Purchases/Additions	24,875	21,127
Sales/Reductions	(4,237)	(271)
Total gains or losses (realized or unrealized):
Included in Net Income (Loss)	(18,395)	(8,953)
Asset balance, end of period	80,409	57,075
Trading securities.
Rollforward for financial instruments measured at fair value using Level 3 inputs
Asset balance, beginning of period	1
Total gains or losses (realized or unrealized):
Asset balance, end of period	1
Available for sale securities
Rollforward for financial instruments measured at fair value using Level 3 inputs
Purchases/Additions		7,301
Total gains or losses (realized or unrealized):
Included in Net Income (Loss)		(1,369)
Asset balance, end of period		5,932
Loans held for sale
Rollforward for financial instruments measured at fair value using Level 3 inputs
Asset balance, beginning of period	25,880	9,017
Purchases/Additions	23,236	11,136
Sales/Reductions	(4,237)	(271)
Total gains or losses (realized or unrealized):
Included in Net Income (Loss)	(4,334)	(387)
Asset balance, end of period	40,545	19,495
MSR
Rollforward for financial instruments measured at fair value using Level 3 inputs
Asset balance, beginning of period	52,285	36,155
Purchases/Additions	1,639	2,690
Total gains or losses (realized or unrealized):
Included in Net Income (Loss)	(14,061)	(7,197)
Asset balance, end of period	$ 39,863	$ 31,648