Summary of Significant Accounting Policies - Litigation and Other Non-Routine Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Merger related costs:
Strategic advisory services	$ 0	$ 0	$ 35,765
Transfer taxes	562	(2,509)	5,109
Legal fees and expenses	0	0	5,464
Personnel costs and other reimbursements	0	0	751
Multi-tenant spin off	0	0	7,450
Other fees and expenses	0	0	1,676
Litigation and other non-routine costs:
Post-transaction support services	0	0	14,251
Subordinated distribution fee	0	0	78,244
Audit Committee Investigation and related matters	24,207	44,242	17,660
Furniture, fixtures and equipment	0	0	14,085
Legal fees and expenses	311	2,704	8,216
Personnel costs and other reimbursements	0	0	2,718
Other fees and expenses	0	632	9,016
Total costs incurred	25,080	45,069	200,405
Insurance recoveries	(21,196)	(11,441)	(789)
Total	$ 3,884	$ 33,628	$ 199,616