Commercial Mortgage Banking - Schedule of Amortization Expense (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Servicing Asset at Amortized Cost [Line Items]
2014	$ 2,098
2015	4,195
2016	4,188
2017	4,154
2018	3,997
Thereafter	10,588
Amortization expense	29,220	$ 30,140	$ 29,115	$ 28,879
Originated MSRs [Member]
Servicing Asset at Amortized Cost [Line Items]
2014	1,484
2015	2,967
2016	2,963
2017	2,934
2018	2,839
Thereafter	8,361
Amortization expense	21,548
Purchased MSRs [Member]
Servicing Asset at Amortized Cost [Line Items]
2014	614
2015	1,228
2016	1,225
2017	1,220
2018	1,158
Thereafter	2,227
Amortization expense	$ 7,672