Fair Value Measurements - Financial instruments not carried at fair value (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Deposit Liabilities		$ 1,168,376	$ 1,245,367
Notes payable and debt	[1]	2,644,970	1,662,580
Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Financial Assets		141,329	354,382
Deposit Liabilities		1,168,376	1,245,367
Notes payable and debt		2,644,970	1,662,580
Financial Liabilities		3,813,346	2,907,947
Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Financial Assets		154,065	371,625
Deposit Liabilities		1,436,210	1,543,761
Notes payable and debt		2,805,152	1,897,854
Financial Liabilities		$ 4,241,362	$ 3,441,615

[1] "In Use/Outstanding" data represent December 31, 2015 and December 31, 2014 accreted values.