Disclosures About Fair Value of Financial Instruments - Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial assets:
Available-for-sale securities	$ 687,100	$ 274,619
Level 1
Financial assets:
Available-for-sale securities		112,881
Level 2
Financial assets:
Available-for-sale securities	687,100	161,738
Recurring [Member]
Financial assets:
Available-for-sale securities	687,100	274,619
Financial Liabilities:
Derivative liability		698
Recurring [Member] | Interest Rate Swap
Financial assets:
Derivative asset		698
Recurring [Member] | Interest Rate Cap
Financial assets:
Derivative asset		1,307
Financial Liabilities:
Derivative liability		1,389
Recurring [Member] | Level 1
Financial assets:
Available-for-sale securities		112,881
Recurring [Member] | Level 2
Financial assets:
Available-for-sale securities	687,100	161,738
Recurring [Member] | Level 2 | Interest Rate Swap
Financial assets:
Derivative asset		698
Recurring [Member] | Level 2 | Interest Rate Cap
Financial assets:
Derivative asset		1,307
Financial Liabilities:
Derivative liability		1,389
Commercial Customer | Recurring [Member] | Interest Rate Swap
Financial assets:
Derivative asset	704
Financial Liabilities:
Derivative liability	676
Commercial Customer | Recurring [Member] | Interest Rate Cap
Financial assets:
Derivative asset	890
Financial Liabilities:
Derivative liability	58	5
Commercial Customer | Recurring [Member] | Level 2 | Interest Rate Swap
Financial assets:
Derivative asset	704
Financial Liabilities:
Derivative liability	676	698
Commercial Customer | Recurring [Member] | Level 2 | Interest Rate Cap
Financial assets:
Derivative asset	890
Financial Liabilities:
Derivative liability	58	5
Correspondent | Recurring [Member] | Interest Rate Cap
Financial assets:
Derivative asset	52	5
Financial Liabilities:
Derivative liability	933
Correspondent | Recurring [Member] | Level 2 | Interest Rate Cap
Financial assets:
Derivative asset	52	$ 5
Financial Liabilities:
Derivative liability	$ 933