Derivative Financial Instruments - Master Netting Arrangements (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	$ 75,207	$ 196,346
Gross Amounts offset in the Statement of Financial Position	(1)	(70)
Net Amounts of Assets Presented in the Statement of Financial Position	75,206	196,276
Gross Assets Subject To Master Netting Arrangement Not Offset	(62,155)	(181,547)
Cash Collateral Received Subject to Master Netting Arrangements	(6,630)	(5,080)
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	6,421	9,649
Gross Amounts of Recognized Liabilities	18,151	14,083
Gross Amounts offset in the Statement of Financial Position	(1)	(70)
Net Amounts of Liabilities Presented in the Statement of Financial Position	18,150	14,013
Gross Liabilities Subject To Master Netting Arrangement Not Offset	(11,611)	(9,648)
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	6,539	4,365
Derivative
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	24,373	23,357
Gross Amounts offset in the Statement of Financial Position	(1)	(70)
Net Amounts of Assets Presented in the Statement of Financial Position	24,372	23,287
Gross Assets Subject To Master Netting Arrangement Not Offset	(11,321)	(8,558)
Cash Collateral Received Subject to Master Netting Arrangements	(6,630)	(5,080)
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	6,421	9,649
Gross Amounts of Recognized Liabilities	18,151	14,083
Gross Amounts offset in the Statement of Financial Position	(1)	(70)
Net Amounts of Liabilities Presented in the Statement of Financial Position	18,150	14,013
Gross Liabilities Subject To Master Netting Arrangement Not Offset	(11,611)	(9,648)
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	6,539	4,365
Derivative | Interest rate swaps
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	4,965	6,492
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	4,965	6,492
Gross Assets Subject To Master Netting Arrangement Not Offset	(1,055)	(1,412)
Cash Collateral Received Subject to Master Netting Arrangements	(3,910)	(5,080)
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	0	0
Derivative | Foreign exchange forwards
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	17,143	15,096
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	17,143	15,096
Gross Assets Subject To Master Netting Arrangement Not Offset	(8,002)	(6,735)
Cash Collateral Received Subject to Master Netting Arrangements	(2,720)	0
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	6,421	8,361
Gross Amounts of Recognized Liabilities	15,742	12,183
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	15,742	12,183
Gross Liabilities Subject To Master Netting Arrangement Not Offset	(9,294)	(8,282)
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	6,448	3,901
Derivative | Client foreign currency options
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	92	504
Gross Amounts offset in the Statement of Financial Position	(1)	(70)
Net Amounts of Assets Presented in the Statement of Financial Position	91	434
Gross Assets Subject To Master Netting Arrangement Not Offset	(91)	(155)
Cash Collateral Received Subject to Master Netting Arrangements	0	0
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	0	279
Gross Amounts of Recognized Liabilities	92	504
Gross Amounts offset in the Statement of Financial Position	(1)	(70)
Net Amounts of Liabilities Presented in the Statement of Financial Position	91	434
Gross Liabilities Subject To Master Netting Arrangement Not Offset	0	(279)
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	91	155
Derivative | Client interest rate derivatives
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	2,173	1,265
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	2,173	1,265
Gross Assets Subject To Master Netting Arrangement Not Offset	(2,173)	(256)
Cash Collateral Received Subject to Master Netting Arrangements	0	0
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	0	1,009
Gross Amounts of Recognized Liabilities	2,317	1,396
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	2,317	1,396
Gross Liabilities Subject To Master Netting Arrangement Not Offset	(2,317)	(1,087)
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	0	309
Reverse Repurchase Securities Borrowing And Similar Arrangements
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	50,834	172,989
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	50,834	172,989
Gross Assets Subject To Master Netting Arrangement Not Offset	(50,834)	(172,989)
Cash Collateral Received Subject to Master Netting Arrangements	0	0
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	0	0
Gross Amounts of Recognized Liabilities	0	0
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	0	0
Gross Liabilities Subject To Master Netting Arrangement Not Offset	0	0
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	$ 0	$ 0