Loans - Activity in Portfolio (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Activity in allowance for loan losses
Allowance for loan losses at the beginning of the period			$ 9,788	$ 6,029
Provision for loan losses			(3,170)	3,395
Allowance for loan losses at the end of the period	$ 6,618	$ 9,424	6,618	9,424
Recorded investment in loans related to the allowance for loan loss	310,046	488,576	310,046	488,576
Activity in loan portfolio
Balance at the beginning of the period			5,946,274	6,263,517
Acquisitions/origination/additional funding			3,722,624	2,795,772
Capitalized Interest			55,987	65,003
Basis of loans sold			(1,024,964)	(1,359,780)
Loan maturities/principal repayments			(1,742,494)	(2,188,583)
Discount accretion/premium amortization			27,014	38,809
Changes in fair value	19,485	49,996	45,484	70,122
Unrealized foreign currency remeasurement loss			31,395	(37,332)
Change in loan loss allowance, net			3,170	(3,395)
Transfer to/from other asset classifications			844	36,566
Balance at the end of the period	$ 7,065,334	$ 5,680,699	$ 7,065,334	$ 5,680,699