Loans Receivable, Net - Credit Grades and Risk Characteristics (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 1,496,628
2019	1,313,707
2018	817,607
2017	800,731
2016	620,952
2015 and prior	2,340,571
Revolving lines of credit	365,910
Total	7,756,106	$ 6,214,652
Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	137,993
2019	42,604
2018	30,036
2017	21,076
2016	34,914
2015 and prior	61,163
Revolving lines of credit	142,870
Total	470,656
Commercial and industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	137,262
2019	40,737
2018	27,967
2017	18,845
2016	33,568
2015 and prior	59,339
Revolving lines of credit	134,140
Total	451,858
Commercial and industrial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	150
2019	583
2018	826
2017	1,422
2016	907
2015 and prior	118
Revolving lines of credit	1,429
Total	5,435
Commercial and industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	581
2019	1,284
2018	1,243
2017	809
2016	439
2015 and prior	1,706
Revolving lines of credit	7,301
Total	13,363
Commercial real estate – owner occupied
Financing Receivable, Credit Quality Indicator [Line Items]
2020	96,888
2019	152,688
2018	140,203
2017	128,477
2016	125,056
2015 and prior	481,743
Revolving lines of credit	20,010
Total	1,145,065
Commercial real estate – owner occupied | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	96,888
2019	114,506
2018	122,962
2017	124,050
2016	104,264
2015 and prior	428,423
Revolving lines of credit	18,932
Total	1,010,025
Commercial real estate – owner occupied | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	3,512
2018	8,240
2017	1,023
2016	17,115
2015 and prior	17,811
Revolving lines of credit	439
Total	48,140
Commercial real estate – owner occupied | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	34,670
2018	9,001
2017	3,404
2016	3,677
2015 and prior	35,509
Revolving lines of credit	639
Total	86,900
Commercial real estate - investor
Financing Receivable, Credit Quality Indicator [Line Items]
2020	640,241
2019	653,631
2018	336,148
2017	458,715
2016	297,584
2015 and prior	904,260
Revolving lines of credit	200,885
Total	3,491,464
Commercial real estate - investor | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	635,930
2019	628,435
2018	317,104
2017	426,268
2016	281,876
2015 and prior	812,062
Revolving lines of credit	194,913
Total	3,296,588
Commercial real estate - investor | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	15,979
2018	17,113
2017	15,225
2016	4,234
2015 and prior	55,872
Revolving lines of credit	149
Total	108,572
Commercial real estate - investor | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	4,311
2019	9,217
2018	1,931
2017	17,222
2016	11,474
2015 and prior	36,326
Revolving lines of credit	5,823
Total	86,304
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,648,921	2,729,155
Consumer | Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	596,552
2019	438,125
2018	227,924
2017	166,994
2016	146,683
2015 and prior	733,181
Revolving lines of credit	0
Total	2,309,459	$ 2,321,157
Consumer | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	24,954
2019	26,659
2018	83,296
2017	25,469
2016	16,715
2015 and prior	160,224
Revolving lines of credit	2,145
Total	339,462
Consumer | Pass | Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	595,982
2019	437,593
2018	226,435
2017	166,773
2016	146,237
2015 and prior	729,037
Revolving lines of credit	0
Total	2,302,057
Consumer | Pass | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	24,954
2019	26,659
2018	83,296
2017	25,469
2016	16,565
2015 and prior	156,276
Revolving lines of credit	2,145
Total	335,364
Consumer | Special Mention | Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	532
2018	0
2017	0
2016	446
2015 and prior	2,186
Revolving lines of credit	0
Total	3,164
Consumer | Special Mention | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	150
2015 and prior	382
Revolving lines of credit	0
Total	532
Consumer | Substandard | Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	570
2019	0
2018	1,489
2017	221
2016	0
2015 and prior	1,958
Revolving lines of credit	0
Total	4,238
Consumer | Substandard | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
2015 and prior	3,566
Revolving lines of credit	0
Total	$ 3,566