| Group (NOKm) | 4Q | 3Q | 2Q | 1Q | 4Q | 3Q | 2Q | 1Q | 4Q | 
| 2017 | 2017 | 2017 | 2017 | 2016 | 2016 | 2016 | 2016 | 2015 | |
| Profitability | |||||||||
| Return on equity per quarter *) | 13.4% | 12.5% | 10.5% | 9.4% | 12.2% | 11.3% | 12.9% | 8.9% | 8.4% | 
| Cost-income ratio*) | 45 % | 45 % | 50 % | 51 % | 42 % | 44 % | 44 % | 46 % | 53 % | 
| Balance sheet figures | |||||||||
| Gross loans to customers | 112,071 | 110,695 | 107,358 | 104,117 | 102,325 | 99,569 | 97,790 | 95,331 | 93,974 | 
| Gross loans incl. SB1 Boligkreditt and SB1 Næringskreditt | 148,784 | 147,146 | 143,800 | 140,038 | 137,535 | 134,462 | 132,583 | 129,520 | 127,378 | 
| Deposits from customers | 76,476 | 73,086 | 75,559 | 70,176 | 67,168 | 66,290 | 67,031 | 63,851 | 64,090 | 
| Total assets | 153,254 | 146,913 | 149,449 | 142,042 | 138,080 | 139,815 | 141,145 | 134,345 | 131,914 | 
| Average total assets | 150,083 | 148,181 | 145,746 | 140,061 | 138,948 | 140,480 | 137,745 | 133,129 | 130,575 | 
| Growth in loans incl. SB1 Boligkreditt and SB1 Næringskredtt last 12 months *) | 8.2 % | 9.4 % | 8.5 % | 8.1 % | 8.0 % | 6.6 % | 6.5 % | 5.4 % | 5.8 % | 
| Growth in deposits last 12 months*) | 13.9 % | 10.3 % | 12.7 % | 9.9 % | 4.8 % | 4.2 % | 1.3 % | 5.4 % | 5.6 % | 
| Losses and defaults in % of gross loans incl. SB1 Boligkreditt and SB1 Næringskreditt | |||||||||
| Impairment losses ratio*) | 0.22 % | 0.24 % | 0.24 % | 0.26 % | 0.28 % | 0.39 % | 0.36 % | 0.53 % | 0.18 % | 
| Non-performing commitm. as a percentage of gross loans*) | 0.19 % | 0.18 % | 0.18 % | 0.15 % | 0.16 % | 0.16 % | 0.19 % | 0.16 % | 0.16 % | 
| Other doubtful commitm. as a percentage of gross loans*) | 0.80 % | 0.83 % | 0.80 % | 0.77 % | 1.07 % | 1.01 % | 0.90 % | 0.32 % | 0.31 % | 
| Solidity | |||||||||
| Common equity tier 1 | 14.9 % | 14.7 % | 15.0 % | 14.8 % | 14.9 % | 14.3 % | 14.1 % | 13.6 % | 13.6 % | 
| Core capital ratio | 16.9 % | 16.6 % | 16.9 % | 16.8 % | 17.0 % | 16.3 % | 16.1 % | 15.6 % | 15.6 % | 
| Capital adequacy ratio | 19.0 % | 19.1 % | 19.1 % | 19.0 % | 19.4 % | 18.8 % | 18.7 % | 18.1 % | 18.3 % | 
| Core capital | 15,824 | 15,807 | 15,622 | 15,254 | 15,069 | 14,736 | 14,604 | 14,237 | 13,988 | 
| Net equity and related capital | 17,746 | 18,093 | 17,649 | 17,288 | 17,185 | 17,011 | 16,882 | 16,516 | 16,378 | 
| Liquidity Coverage Ratio (LCR) | 164 % | 124 % | 160 % | 136 % | 129 % | 138 % | 149 % | 110 % | 118 % | 
| Leverage Ratio | 7.2 % | 7.5 % | 7.2 % | 7.4 % | 7.4 % | 7.1 % | 6.8 % | 6.8 % | 6.7 % | 
| Key figures ECC *) | |||||||||
| ECC share price at end of period (NOK) | 82.25 | 81.25 | 71.75 | 66.50 | 64.75 | 55.75 | 46.70 | 52.75 | 50.50 | 
| Number of certificates issued, millions*) | 129.38 | 129.40 | 129.54 | 129.48 | 129.64 | 129.66 | 129.47 | 129.47 | 129.43 | 
| Booked equity capital per ECC (including dividend)*) | 78.81 | 79.18 | 75.40 | 72.31 | 73.35 | 74.71 | 71.53 | 68.38 | 67.39 | 
| Profit per ECC, majority*) | 2.63 | 2.42 | 1.92 | 1.74 | 2.21 | 2.00 | 2.22 | 1.50 | 1.43 | 
| Price-Earnings Ratio*) | 7.81 | 8.40 | 9.32 | 9.58 | 7.32 | 6.97 | 5.26 | 8.81 | 8.80 | 
| Price-Book Value Ratio*) | 1.04 | 1.03 | 0.95 | 0.92 | 0.88 | 0.75 | 0.65 | 0.77 | 0.75 | 
| *) Defined as alternative performance measures, see attachment to the quarterly report. | |||||||||