Derivatives and Hedging - Netting Arrangements (Details) - USD ($) $ in Thousands		Mar. 31, 2017	Dec. 31, 2016
Derivative financial assets:
Derivative assets, total derivatives subject to a master netting arrangement, gross amounts recognized		$ 203,289	$ 234,002
Derivative assets, total derivative subject to a master netting arrangement, gross amounts offset in the condensed consolidated balance sheet		0	0
Derivative assets, total derivatives subject to a master netting arrangement, net amount presented in the condensed consolidated balance sheets		203,289	234,002
Derivative assets, total derivatives subject to a master netting arrangement, financial instruments collateral received/pledged	[1]	0	0
Derivate assets, total derivatives subject to a master netting arrangement, cash collateral received/pledged	[1]	41,212	33,212
Derivative asset, total derivatives subject to a master netting arrangement, net amount		162,077	200,790
Derivative assets, total derivatives not subject to a master netting arrangement		162,593	191,809
Derivative assets, total derivatives not subject to a master netting arrangement, net amount		162,593	191,809
Total derivative financial assets, gross amounts recognized		365,882	425,811
Total derivative financial assets, net amount presented in the condensed consolidated balance sheet		365,882	425,811
Total derivative financial assets, net amount		324,670	392,599
Derivative financial liabilities:
Derivative liabilities, total derivative subject to a master netting arrangement, gross amounts recognized		220,530	248,669
Derivative liabilities, total derivative subject to a master netting arrangement, gross amount offset in the condensed consolidated balance sheets		0	0
Derivative liabilities, total derivative subject to a master netting arrangement, net amount presented in the condensed consolidated balance sheets		220,530	248,669
Derivative liabilities, total derivatives subject to a master netting arrangement, financial instruments collateral received/pledged	[1]	8,384	9,685
Derivative liabilities, total derivative subject to a master netting arrangement, cash collateral received/pledged	[1]	86,569	102,603
Derivate liabilities, total derivatives subject to master netting arrangement, net amount		125,577	136,381
Derivative liabilities, total derivatives not subject to a master netting arrangement		104,505	96,665
Derivative liabilities, total derivatives not subject to a master netting arrangement, net amount		104,505	96,665
Derivative liabilities, total derivative financial liabilities, gross amount recognized		325,035	345,334
Total derivative financial liabilities, net amount presented in the condensed consolidated balance sheets		325,035	345,334
Total derivative financial liabilities, net amount		$ 230,082	$ 233,046

[1] The actual amount of collateral received/pledged is limited to the asset/liability balance and does not include excess collateral received/pledged. When excess collateral exists, the collateral shown in the table above has been allocated based on the percentage of the actual amount of collateral posted.