Investment Securities - Amortized Cost of Held to Maturity Debt Securities by External Credit Rating (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	$ 3,828,984	$ 2,668,697
U.S. Treasury securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	66,911	67,558
U.S. government agency securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	260,392	6,265
Obligations of states and state agencies
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	99,238	141,015
Municipal bonds
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	381,060	196,947
Obligations of states and political subdivisions
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	480,298	337,962
Residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	2,909,106	2,166,142
Trust preferred securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	37,043	37,020
Corporate and other debt securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	75,234	53,750
AAA/AA/A Rated
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	3,646,840	2,509,187
AAA/AA/A Rated | U.S. Treasury securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	66,911	67,558
AAA/AA/A Rated | U.S. government agency securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	260,392	6,265
AAA/AA/A Rated | Obligations of states and state agencies
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	74,943	118,368
AAA/AA/A Rated | Municipal bonds
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	333,488	148,854
AAA/AA/A Rated | Obligations of states and political subdivisions
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	408,431	267,222
AAA/AA/A Rated | Residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	2,909,106	2,166,142
AAA/AA/A Rated | Trust preferred securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities		0
AAA/AA/A Rated | Corporate and other debt securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	2,000	2,000
BBB rated
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	6,000	6,000
BBB rated | U.S. Treasury securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
BBB rated | U.S. government agency securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
BBB rated | Obligations of states and state agencies
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
BBB rated | Municipal bonds
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
BBB rated | Obligations of states and political subdivisions
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
BBB rated | Residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
BBB rated | Trust preferred securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
BBB rated | Corporate and other debt securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	6,000	6,000
Non-investment grade rated
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	5,497	5,576
Non-investment grade rated | U.S. Treasury securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
Non-investment grade rated | U.S. government agency securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
Non-investment grade rated | Obligations of states and state agencies
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	5,497	5,576
Non-investment grade rated | Municipal bonds
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
Non-investment grade rated | Obligations of states and political subdivisions
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	5,497	5,576
Non-investment grade rated | Residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
Non-investment grade rated | Trust preferred securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
Non-investment grade rated | Corporate and other debt securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
Non-rated
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	170,647	147,934
Non-rated | U.S. Treasury securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
Non-rated | U.S. government agency securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
Non-rated | Obligations of states and state agencies
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	18,798	17,071
Non-rated | Municipal bonds
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	47,572	48,093
Non-rated | Obligations of states and political subdivisions
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	66,370	65,164
Non-rated | Residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	0	0
Non-rated | Trust preferred securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	37,043	37,020
Non-rated | Corporate and other debt securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost of held to maturity debt securities	$ 67,234	$ 45,750