Securities - Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	$ 372,498	$ 203,525
Held to Maturity, Fair Value, Total	369,881	202,813
Available for Sale, Amortized Cost, Total	960,809
Available for Sale, Fair Value, Total	950,503	790,766
Collateralized Loan Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Due in less than one year	0
Held to Maturity, Fair Value, Due in less than one year	0
Available for Sale Amortized Cost, Due in less than one year	8,848
Available for Sale, Fair Value, Due in less than one year	9,044
Held to Maturity, Amortized Cost, Due after one year through five years	0
Held to Maturity, Fair Value, Due after one year through five years	0
Available for Sale, Amortized Cost, Due after one year through five years	83,308
Available for Sale, Fair Value, Due after one year through five years	83,154
Held to Maturity, Amortized Cost, Due after five years through ten years	41,547
Held to Maturity, Fair Value, Due after five years through ten years	41,663
Available for Sale, Amortized Cost, Due after five years through ten years	139,611
Available for Sale, Fair Value, Due after five years through ten years	140,167
Held to Maturity, Amortized Cost, Due after ten years	0
Held to Maturity, Fair Value, Due after ten years	0
Available for Sale, Amortized Cost, Due after ten years	31,415
Available for Sale, Fair Value, Due after ten years	30,709
Held to Maturity, Amortized Cost, Total	41,547
Held to Maturity, Fair Value, Total	41,663
Available for Sale, Amortized Cost, Total	263,182
Available for Sale, Fair Value, Total	263,074
Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	159,941
Held to Maturity, Fair Value, Total	159,402	65,551
Available for Sale, Amortized Cost, Total	287,726
Available for Sale, Fair Value, Total	283,488	191,749
Collateralized Mortgage Obligations Of US Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	147,208
Held to Maturity, Fair Value, Total	144,964	89,440
Available for Sale, Amortized Cost, Total	238,805
Available for Sale, Fair Value, Total	234,054	238,190
Private mortgage backed securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	0
Held to Maturity, Fair Value, Total	0
Available for Sale, Amortized Cost, Total	32,780
Available for Sale, Fair Value, Total	31,989	31,792
Private collateralized mortgage obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	6,427
Held to Maturity, Fair Value, Total	6,318	7,882
Available for Sale, Amortized Cost, Total	67,542
Available for Sale, Fair Value, Total	67,289	77,957
Corporate and other debt securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	0
Held to Maturity, Fair Value, Total	0
Available for Sale, Amortized Cost, Total	10,889
Available for Sale, Fair Value, Total	73,861	44,273
Private commercial mortgage backed securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	0
Held to Maturity, Fair Value, Total	0
Available for Sale, Amortized Cost, Total	37,534
Available for Sale, Fair Value, Total	37,172	$ 40,420
Commercial mortgage backed securities of U.S. Government Sponsored Entities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost, Total	17,375
Held to Maturity, Fair Value, Total	17,534
Available for Sale, Amortized Cost, Total	22,351
Available for Sale, Fair Value, Total	$ 22,545