Benefit Plans Stock-Based Compensation - Narrative (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Total compensation expense | $ 622,000 | $ 440,000 | $ 384,000 |
| Stock Options | |||
| Share-based Compensation Arrangement by Share-based Payment Award, Description | The Plan authorized the grant of stock options amounting to 2,285,280 shares to Company directors, advisory directors, officers, and employees. Option awards are granted with an exercise price equal to the market price of First Financial Northwest’s common stock at the grant date. | ||
| Share-based Compensation Arrangement by Share-based Payment | These option awards have a vesting period of five years, with 20% vesting on the anniversary date of each grant date, and a contractual life of ten years. Any unexercised stock options will expire ten years after the grant date, or sooner in the event of the award recipient’s death, disability or termination of service with the Company. | ||
| Restricted Stock | |||
| Share-based Compensation Arrangement by Share-based Payment Award, Description | The Plan authorized the grant of restricted stock awards amounting to 914,112 shares to directors, advisory directors, officers and employees. Compensation expense is recognized over the vesting period of the awards based on the fair value of the stock at the grant date. The restricted stock awards’ fair value is equal to the value on the grant date. Shares awarded as restricted stock vest ratably over a five-year period beginning at the grant date with 20% vesting on the anniversary date of each grant date. | ||
| First Financial Northwest, Inc. 2008 Equity Incentive Plan | |||
| Compensation expense, related tax benefit | $ 218,000 | 154,000 | $ 134,000 |
| First Financial Northwest, Inc. 2008 Equity Incentive Plan | Stock Options | |||
| Award vesting period | 5 years | ||
| Percentage vesting per annum | 20.00% | ||
| Contractual life | 10 years | ||
| Number of shares remaining for grant | 611,756 | ||
| Unrecognized compensation cost | $ 590,000 | ||
| Unrecognized compensation cost recognition period | 2 years 9 months | ||
| First Financial Northwest, Inc. 2008 Equity Incentive Plan | Restricted Stock | |||
| Award vesting period | 5 years | ||
| Percentage vesting per annum | 20.00% | ||
| Number of shares remaining for grant | 74,478 | ||
| Unrecognized compensation cost | $ 177,000 | ||
| Unrecognized compensation cost recognition period | 1 year 1 month | ||
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value | $ 367,000 | $ 212,000 | |
| First Financial Northwest Inc 2016 Equity Incentive Plan [Member] | Stock Options | |||
| Stock options granted (shares) | 1,400,000 | ||
| Number of shares remaining for grant | 1,371,896 | ||
| First Financial Northwest Inc 2016 Equity Incentive Plan [Member] | Restricted Stock | |||
| Stock options granted (shares) | 400,000 | ||
| Number of shares remaining for grant | 385,948 | ||