XML 37 R24.htm IDEA: XBRL DOCUMENT v3.21.2
Investment Securities (Tables)
 6 Months Ended
Jun. 30, 2021
Investments, Debt and Equity Securities [Abstract]  
Schedule of Amortized Cost and Fair Values of Investment Securities
The following table presents the amortized cost and estimated fair values of investment securities for the periods presented:
June 30, 2021
Amortized
Cost		Gross
Unrealized
Gains		Gross
Unrealized
Losses		Estimated
Fair
Value
Available for Sale(in thousands)
U.S. Government securities$153,885 $— $(340)$153,545 
U.S. Government sponsored agency securities62,529 — (98)62,431 
State and municipal securities1,002,146 53,924 (608)1,055,462 
Corporate debt securities354,593 16,876 (88)371,381 
Collateralized mortgage obligations299,333 7,965 (133)307,165 
Residential mortgage-backed securities201,654 1,641 (1,748)201,547 
Commercial mortgage-backed securities858,574 14,338 (1,902)871,010 
Auction rate securities76,350 — (1,516)74,834 
   Total $3,009,064 $94,744 $(6,433)$3,097,375 
Held to Maturity
Residential mortgage-backed securities$439,220 $15,470 $(5,019)$449,671 
Commercial mortgage-backed securities385,063 — (7,802)377,261 
Total $824,283 $15,470 $(12,821)$826,932 

December 31, 2020
Amortized
Cost		Gross
Unrealized
Gains		Gross
Unrealized
Losses		Estimated
Fair
Value
Available for Sale(in thousands)
State and municipal securities$891,327 $61,286 $— $952,613 
Corporate debt securities348,391 19,445 (691)367,145 
Collateralized mortgage obligations491,321 12,560 (115)503,766 
Residential mortgage-backed securities373,779 4,246 (27)377,998 
Commercial mortgage-backed securities741,172 22,384 (1,141)762,415 
Auction rate securities101,510 — (3,304)98,206 
   Total $2,947,500 $119,921 $(5,278)$3,062,143 
Held to Maturity
Residential mortgage-backed securities$278,281 $18,576 $— $296,857 
Schedule of Amortized Cost and Fair Values of Debt Securities by Contractual Maturities
The amortized cost and estimated fair values of debt securities as of June 30, 2021, by contractual maturity, are shown in the following table. Actual maturities may differ from contractual maturities as certain investment securities are subject to call or prepayment with or without call or prepayment penalties.
June 30, 2021
Available for SaleHeld to Maturity
 Amortized
Cost		Estimated
Fair Value		Amortized
Cost		Estimated
Fair Value
 (in thousands)
Due in one year or less$8,212 $8,240 $— $— 
Due from one year to five years253,200 253,976 — — 
Due from five years to ten years353,124 371,026 — — 
Due after ten years1,034,967 1,084,411 — — 
1,649,503 1,717,653 — — 
Residential mortgage-backed securities(1)
201,654 201,547 439,220 449,671 
Commercial mortgage-backed securities(1)
858,574 871,010 385,063 377,261 
Collateralized mortgage obligations(1)
299,333 307,165 — — 
  Total$3,009,064 $3,097,375 $824,283 $826,932 
(1) Mortgage-backed securities and collateralized mortgage obligations do not have stated maturities and are dependent upon the interest rate environment and prepayments on the underlying loans.
Summary of Gains and Losses from Equity and Debt Securities, and Losses Recognized from Other-than-Temporary Impairment
The following table presents information related to the gross realized gains and losses on the sales of investment securities for the periods presented:
Gross Realized GainsGross Realized LossesNet Gains
Three months ended(in thousands)
June 30, 2021$465 $(429)$36 
June 30, 20206,334 (3,329)3,005 
Six months ended
June 30, 2021$34,481 $(970)$33,511 
June 30, 20206,451 (3,400)3,051 
Gross Unrealized Losses and Fair Values of Investments by Category and Length of Time in Continuous Unrealized Loss Position
The following tables present the gross unrealized losses and estimated fair values of investment securities, aggregated by category and length of time that individual securities have been in a continuous unrealized loss position for the periods presented:
June 30, 2021
Less than 12 months12 months or longerTotal
Number of SecuritiesEstimated
Fair Value		Unrealized
Losses		Number of SecuritiesEstimated
Fair Value		Unrealized
Losses		Estimated
Fair Value		Unrealized
Losses
Available for Sale(in thousands)
U.S. Government securities2$153,545 $(340)— $— $— $153,545 $(340)
U.S. Government sponsored agency securities162,431 (98)— — — 62,431 (98)
State and municipal securities12 46,851 (608)— — — 46,851 (608)
Corporate debt securities5 19,921 (88)— — — 19,921 (88)
Collateralized mortgage obligations1 30,402 (133)— — — 30,402 (133)
Residential mortgage-backed securities7 154,928 (1,748)— — — 154,928 (1,748)
Commercial mortgage-backed securities15 241,220 (1,902)— — — 241,220 (1,902)
Auction rate securities— — — 118 74,834 (1,516)74,834 (1,516)
Total available for sale43 $709,298 $(4,917)118 $74,834 $(1,516)$784,132 $(6,433)
Held to Maturity
Residential mortgage-backed securities12 $203,077 $(5,019)— $— $— $203,077 $(5,019)
Commercial mortgage-backed securities21 377,261 (7,802)— — — 377,261 (7,802)
Total 33 $580,338 $(12,821)— $— $— $580,338 $(12,821)

December 31, 2020
Less than 12 months12 months or longerTotal
Number of SecuritiesEstimated
Fair Value		Unrealized
Losses		Number of SecuritiesEstimated
Fair Value		Unrealized
Losses		Estimated
Fair Value		Unrealized
Losses
Available for Sale(in thousands)
Corporate debt securities9 $44,528 $(377)1 $6,871 $(314)$51,399 $(691)
Collateralized mortgage obligations3 57,601 (115)— — — 57,601 (115)
Residential mortgage-backed securities1 20,124 (27)— — — 20,124 (27)
Commercial mortgage-backed securities9 144,383 (1,141)— — — 144,383 (1,141)
Auction rate securities— — — 162 98,206 (3,304)98,206 (3,304)
Total available for sale(1)
22 $266,636 $(1,660)163 $105,077 $(3,618)$371,713 $(5,278)
(1) No HTM securities were in an unrealized loss position as of December 31, 2020.