Debt and Equity Securities (Tables)
|
3 Months Ended |
Mar. 31, 2018 |
|---|
| Investments Debt And Equity Securities [Abstract] |
|
| Investments in Debt Securities, Classified as Available-For-Sale |
Investments in debt securities, classified as available-for-sale, are as follows:
|
(in thousands) |
Amortized
cost |
|
|
Gross unrealized |
|
|
Estimated
fair value |
|
|
Gains |
|
|
Losses |
|
|
March 31, 2018 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. Treasury bonds |
$ |
189,322 |
|
|
$ |
602 |
|
|
$ |
(3,146 |
) |
|
$ |
186,778 |
|
|
Municipal bonds |
|
1,104,512 |
|
|
|
6,013 |
|
|
|
(18,648 |
) |
|
|
1,091,877 |
|
|
Foreign government bonds |
|
155,001 |
|
|
|
176 |
|
|
|
(2,151 |
) |
|
|
153,026 |
|
|
Governmental agency bonds |
|
223,473 |
|
|
|
680 |
|
|
|
(4,471 |
) |
|
|
219,682 |
|
|
Governmental agency mortgage-backed securities |
|
2,325,348 |
|
|
|
2,692 |
|
|
|
(33,744 |
) |
|
|
2,294,296 |
|
|
U.S. corporate debt securities |
|
731,649 |
|
|
|
4,721 |
|
|
|
(10,054 |
) |
|
|
726,316 |
|
|
Foreign corporate debt securities |
|
263,396 |
|
|
|
1,631 |
|
|
|
(2,892 |
) |
|
|
262,135 |
|
|
|
$ |
4,992,701 |
|
|
$ |
16,515 |
|
|
$ |
(75,106 |
) |
|
$ |
4,934,110 |
|
|
December 31, 2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. Treasury bonds |
$ |
173,049 |
|
|
$ |
2,199 |
|
|
$ |
(1,250 |
) |
|
$ |
173,998 |
|
|
Municipal bonds |
|
1,031,146 |
|
|
|
12,185 |
|
|
|
(7,394 |
) |
|
|
1,035,937 |
|
|
Foreign government bonds |
|
170,220 |
|
|
|
489 |
|
|
|
(1,221 |
) |
|
|
169,488 |
|
|
Governmental agency bonds |
|
212,731 |
|
|
|
1,061 |
|
|
|
(2,322 |
) |
|
|
211,470 |
|
|
Governmental agency mortgage-backed securities |
|
2,172,377 |
|
|
|
3,168 |
|
|
|
(16,588 |
) |
|
|
2,158,957 |
|
|
U.S. corporate debt securities |
|
734,409 |
|
|
|
11,768 |
|
|
|
(2,962 |
) |
|
|
743,215 |
|
|
Foreign corporate debt securities |
|
256,430 |
|
|
|
4,145 |
|
|
|
(956 |
) |
|
|
259,619 |
|
|
|
$ |
4,750,362 |
|
|
$ |
35,015 |
|
|
$ |
(32,693 |
) |
|
$ |
4,752,684 |
|
|
| Gross Unrealized Losses on Investments in Debt Securities |
Gross unrealized losses on investments in debt securities are as follows:
|
|
Less than 12 months |
|
|
12 months or longer |
|
|
Total |
|
|
(in thousands) |
Estimated
fair value |
|
|
Unrealized
losses |
|
|
Estimated
fair value |
|
|
Unrealized
losses |
|
|
Estimated
fair value |
|
|
Unrealized
losses |
|
|
March 31, 2018 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. Treasury bonds |
$ |
109,820 |
|
|
$ |
(2,009 |
) |
|
$ |
38,554 |
|
|
$ |
(1,137 |
) |
|
$ |
148,374 |
|
|
$ |
(3,146 |
) |
|
Municipal bonds |
|
503,940 |
|
|
|
(6,441 |
) |
|
|
217,817 |
|
|
|
(12,207 |
) |
|
|
721,757 |
|
|
|
(18,648 |
) |
|
Foreign government bonds |
|
93,606 |
|
|
|
(1,397 |
) |
|
|
13,963 |
|
|
|
(754 |
) |
|
|
107,569 |
|
|
|
(2,151 |
) |
|
Governmental agency bonds |
|
97,136 |
|
|
|
(1,542 |
) |
|
|
93,289 |
|
|
|
(2,929 |
) |
|
|
190,425 |
|
|
|
(4,471 |
) |
|
Governmental agency mortgage-backed securities |
|
976,932 |
|
|
|
(15,420 |
) |
|
|
766,336 |
|
|
|
(18,324 |
) |
|
|
1,743,268 |
|
|
|
(33,744 |
) |
|
U.S. corporate debt securities |
|
383,413 |
|
|
|
(7,256 |
) |
|
|
56,030 |
|
|
|
(2,798 |
) |
|
|
439,443 |
|
|
|
(10,054 |
) |
|
Foreign corporate debt securities |
|
154,534 |
|
|
|
(2,604 |
) |
|
|
5,959 |
|
|
|
(288 |
) |
|
|
160,493 |
|
|
|
(2,892 |
) |
|
|
$ |
2,319,381 |
|
|
$ |
(36,669 |
) |
|
$ |
1,191,948 |
|
|
$ |
(38,437 |
) |
|
$ |
3,511,329 |
|
|
$ |
(75,106 |
) |
|
December 31, 2017 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. Treasury bonds |
$ |
78,605 |
|
|
$ |
(511 |
) |
|
$ |
37,498 |
|
|
$ |
(739 |
) |
|
$ |
116,103 |
|
|
$ |
(1,250 |
) |
|
Municipal bonds |
|
279,292 |
|
|
|
(1,714 |
) |
|
|
226,895 |
|
|
|
(5,680 |
) |
|
|
506,187 |
|
|
|
(7,394 |
) |
|
Foreign government bonds |
|
98,942 |
|
|
|
(972 |
) |
|
|
6,678 |
|
|
|
(249 |
) |
|
|
105,620 |
|
|
|
(1,221 |
) |
|
Governmental agency bonds |
|
55,707 |
|
|
|
(409 |
) |
|
|
93,737 |
|
|
|
(1,913 |
) |
|
|
149,444 |
|
|
|
(2,322 |
) |
|
Governmental agency mortgage-backed securities |
|
671,871 |
|
|
|
(4,868 |
) |
|
|
774,959 |
|
|
|
(11,720 |
) |
|
|
1,446,830 |
|
|
|
(16,588 |
) |
|
U.S. corporate debt securities |
|
171,817 |
|
|
|
(1,568 |
) |
|
|
60,724 |
|
|
|
(1,394 |
) |
|
|
232,541 |
|
|
|
(2,962 |
) |
|
Foreign corporate debt securities |
|
81,525 |
|
|
|
(821 |
) |
|
|
5,697 |
|
|
|
(135 |
) |
|
|
87,222 |
|
|
|
(956 |
) |
|
|
$ |
1,437,759 |
|
|
$ |
(10,863 |
) |
|
$ |
1,206,188 |
|
|
$ |
(21,830 |
) |
|
$ |
2,643,947 |
|
|
$ |
(32,693 |
) |
|
| Investments in Debt Securities |
Investments in debt securities at March 31, 2018, by contractual maturities, are as follows:
|
(in thousands) |
Due in one
year or less |
|
|
Due after
one through
five years |
|
|
Due after
five through
ten years |
|
|
Due after
ten years |
|
|
Total |
|
|
U.S. Treasury bonds |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Amortized cost |
$ |
37,530 |
|
|
$ |
55,856 |
|
|
$ |
44,730 |
|
|
$ |
51,206 |
|
|
$ |
189,322 |
|
|
Estimated fair value |
$ |
37,388 |
|
|
$ |
54,931 |
|
|
$ |
43,790 |
|
|
$ |
50,669 |
|
|
$ |
186,778 |
|
|
Municipal bonds |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Amortized cost |
$ |
70,776 |
|
|
$ |
293,994 |
|
|
$ |
272,117 |
|
|
$ |
467,625 |
|
|
$ |
1,104,512 |
|
|
Estimated fair value |
$ |
70,767 |
|
|
$ |
293,665 |
|
|
$ |
269,827 |
|
|
$ |
457,618 |
|
|
$ |
1,091,877 |
|
|
Foreign government bonds |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Amortized cost |
$ |
13,139 |
|
|
$ |
113,211 |
|
|
$ |
12,517 |
|
|
$ |
16,134 |
|
|
$ |
155,001 |
|
|
Estimated fair value |
$ |
13,143 |
|
|
$ |
112,212 |
|
|
$ |
12,430 |
|
|
$ |
15,241 |
|
|
$ |
153,026 |
|
|
Governmental agency bonds |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Amortized cost |
$ |
31,347 |
|
|
$ |
78,487 |
|
|
$ |
65,136 |
|
|
$ |
48,503 |
|
|
$ |
223,473 |
|
|
Estimated fair value |
$ |
31,210 |
|
|
$ |
76,941 |
|
|
$ |
64,331 |
|
|
$ |
47,200 |
|
|
$ |
219,682 |
|
|
U.S. corporate debt securities |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Amortized cost |
$ |
21,390 |
|
|
$ |
321,444 |
|
|
$ |
315,735 |
|
|
$ |
73,080 |
|
|
$ |
731,649 |
|
|
Estimated fair value |
$ |
21,431 |
|
|
$ |
318,706 |
|
|
$ |
312,509 |
|
|
$ |
73,670 |
|
|
$ |
726,316 |
|
|
Foreign corporate debt securities |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Amortized cost |
$ |
18,674 |
|
|
$ |
137,519 |
|
|
$ |
94,093 |
|
|
$ |
13,110 |
|
|
$ |
263,396 |
|
|
Estimated fair value |
$ |
18,701 |
|
|
$ |
136,902 |
|
|
$ |
93,212 |
|
|
$ |
13,320 |
|
|
$ |
262,135 |
|
|
Total debt securities excluding mortgage-backed securities |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Amortized cost |
$ |
192,856 |
|
|
$ |
1,000,511 |
|
|
$ |
804,328 |
|
|
$ |
669,658 |
|
|
$ |
2,667,353 |
|
|
Estimated fair value |
$ |
192,640 |
|
|
$ |
993,357 |
|
|
$ |
796,099 |
|
|
$ |
657,718 |
|
|
$ |
2,639,814 |
|
|
Total mortgage-backed securities |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Amortized cost |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
$ |
2,325,348 |
|
|
Estimated fair value |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
$ |
2,294,296 |
|
|
Total debt securities |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Amortized cost |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
$ |
4,992,701 |
|
|
Estimated fair value |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
$ |
4,934,110 |
|
|
| Investments in Equity Securities |
Investments in equity securities are as follows:
|
|
Cost |
|
Estimated
fair value |
|
|
(in thousands) |
|
|
|
March 31, 2018 |
|
|
|
|
|
|
|
Preferred stocks |
$ |
18,692 |
|
$ |
18,238 |
|
|
Common stocks |
|
405,633 |
|
|
441,239 |
|
|
|
$ |
424,325 |
|
$ |
459,477 |
|
|
December 31, 2017 |
|
|
|
|
|
|
|
Preferred stocks |
$ |
19,233 |
|
$ |
18,990 |
|
|
Common stocks |
|
394,439 |
|
|
447,526 |
|
|
|
$ |
413,672 |
|
$ |
466,516 |
|
|
| Composition of Investment Portfolio by Credit Rating Agencies |
The composition of the investment portfolio at March 31, 2018, by credit rating, is as follows:
|
|
A- or higher |
|
|
BBB+ to BBB- |
|
|
Non-Investment Grade |
|
|
Total |
|
|
(in thousands, except percentages) |
Estimated
fair value |
|
|
|
Percentage |
|
|
Estimated
fair value |
|
|
|
Percentage |
|
|
Estimated
fair value |
|
|
|
Percentage |
|
|
Estimated
fair value |
|
|
|
Percentage |
|
|
March 31, 2018 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Debt securities: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. Treasury bonds |
$ |
186,778 |
|
|
|
100.0 |
|
|
$ |
— |
|
|
|
— |
|
|
$ |
— |
|
|
|
— |
|
|
$ |
186,778 |
|
|
|
100.0 |
|
|
Municipal bonds |
|
1,012,141 |
|
|
|
92.7 |
|
|
|
59,627 |
|
|
|
5.5 |
|
|
|
20,109 |
|
|
|
1.8 |
|
|
|
1,091,877 |
|
|
|
100.0 |
|
|
Foreign government bonds |
|
123,117 |
|
|
|
80.5 |
|
|
|
24,484 |
|
|
|
16.0 |
|
|
|
5,425 |
|
|
|
3.5 |
|
|
|
153,026 |
|
|
|
100.0 |
|
|
Governmental agency bonds |
|
219,682 |
|
|
|
100.0 |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
219,682 |
|
|
|
100.0 |
|
|
Governmental agency mortgage-backed securities |
|
2,294,296 |
|
|
|
100.0 |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
2,294,296 |
|
|
|
100.0 |
|
|
U.S. corporate debt securities |
|
259,578 |
|
|
|
35.7 |
|
|
|
239,276 |
|
|
|
32.9 |
|
|
|
227,462 |
|
|
|
31.4 |
|
|
|
726,316 |
|
|
|
100.0 |
|
|
Foreign corporate debt securities |
|
122,163 |
|
|
|
46.6 |
|
|
|
108,273 |
|
|
|
41.3 |
|
|
|
31,699 |
|
|
|
12.1 |
|
|
|
262,135 |
|
|
|
100.0 |
|
|
Total debt securities |
|
4,217,755 |
|
|
|
85.5 |
|
|
|
431,660 |
|
|
|
8.7 |
|
|
|
284,695 |
|
|
|
5.8 |
|
|
|
4,934,110 |
|
|
|
100.0 |
|
|
Preferred stocks |
|
— |
|
|
|
— |
|
|
|
13,369 |
|
|
|
73.3 |
|
|
|
4,869 |
|
|
|
26.7 |
|
|
|
18,238 |
|
|
|
100.0 |
|
|
Total |
$ |
4,217,755 |
|
|
|
85.2 |
|
|
$ |
445,029 |
|
|
|
9.0 |
|
|
$ |
289,564 |
|
|
|
5.8 |
|
|
$ |
4,952,348 |
|
|
|
100.0 |
|
|
| Composition of Debt Securities Portfolio in Unrealized Loss Position by Credit Rating Agencies |
The composition of the debt securities portfolio in an unrealized loss position at March 31, 2018, by credit rating, is as follows:
|
|
A- or higher |
|
|
BBB+ to BBB- |
|
|
Non-Investment Grade |
|
|
Total |
|
|
(in thousands, except percentages) |
Estimated
fair value |
|
|
|
Percentage |
|
|
Estimated
fair value |
|
|
|
Percentage |
|
|
Estimated
fair value |
|
|
|
Percentage |
|
|
Estimated
fair value |
|
|
|
Percentage |
|
|
March 31, 2018 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. Treasury bonds |
$ |
148,374 |
|
|
|
100.0 |
|
|
$ |
— |
|
|
|
— |
|
|
$ |
— |
|
|
|
— |
|
|
$ |
148,374 |
|
|
|
100.0 |
|
|
Municipal bonds |
|
683,529 |
|
|
|
94.7 |
|
|
|
36,359 |
|
|
|
5.0 |
|
|
|
1,869 |
|
|
|
0.3 |
|
|
|
721,757 |
|
|
|
100.0 |
|
|
Foreign government bonds |
|
80,575 |
|
|
|
74.9 |
|
|
|
23,833 |
|
|
|
22.2 |
|
|
|
3,161 |
|
|
|
2.9 |
|
|
|
107,569 |
|
|
|
100.0 |
|
|
Governmental agency bonds |
|
190,425 |
|
|
|
100.0 |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
190,425 |
|
|
|
100.0 |
|
|
Governmental agency mortgage-backed securities |
|
1,743,268 |
|
|
|
100.0 |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
— |
|
|
|
1,743,268 |
|
|
|
100.0 |
|
|
U.S. corporate debt securities |
|
195,799 |
|
|
|
44.6 |
|
|
|
172,175 |
|
|
|
39.2 |
|
|
|
71,469 |
|
|
|
16.2 |
|
|
|
439,443 |
|
|
|
100.0 |
|
|
Foreign corporate debt securities |
|
74,495 |
|
|
|
46.4 |
|
|
|
69,761 |
|
|
|
43.5 |
|
|
|
16,237 |
|
|
|
10.1 |
|
|
|
160,493 |
|
|
|
100.0 |
|
|
Total |
$ |
3,116,465 |
|
|
|
88.8 |
|
|
$ |
302,128 |
|
|
|
8.6 |
|
|
$ |
92,736 |
|
|
|
2.6 |
|
|
$ |
3,511,329 |
|
|
|
100.0 |
|
|