Subsequent Event	9 Months Ended
Sep. 30, 2013
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On October 23, 2013, the Company, along with the Bank, and Washington Banking Company (“Washington Banking”) and its wholly owned subsidiary bank, Whidbey Island Bank ("Whidbey") jointly announced the signing of a merger agreement under which Heritage and Washington Banking will enter into a strategic merger with Washington Banking merging into Heritage. Immediately following the merger, Whidbey will merge into the Bank. Washington Banking branches will adopt the Heritage Bank name in all markets, with the exception of six branches in Whidbey Island markets which will continue to operate using the Whidbey Island Bank name. The corporate headquarters of the combined company will be in Olympia, Washington. Under the terms of the merger agreement, Washington Banking shareholders will receive 0.89000 shares of Heritage common stock and $2.75 in cash for each share of Washington Banking common stock. Based on the closing price of Heritage common stock of $15.89 on October 23, 2013, the consideration value per share for Washington Banking was $16.89, or approximately $265.1 million in aggregate. Upon consummation, the shareholders of Washington Banking will own approximately 46% of the combined company and the shareholders of Heritage will own approximately 54%. As of September 30, 2013, Washington Banking had approximately $1.6 billion in total assets. The merger agreement has been unanimously approved by the boards of directors of Heritage and Washington Banking. The merger is subject to regulatory approvals, approval by Heritage and Washington Banking shareholders, and certain other customary closing conditions and is expected to close in the first half of 2014. The transaction is intended to qualify as a tax-free reorganization for U.S. federal income tax purposes and Washington Banking shareholders are not expected to recognize any taxable gain or loss in connection with the share exchange to the extent of the stock consideration received. For further information, reference is made to the Form 8-K filed by the Company with the SEC on October 24, 2013.

Subsequent Event

On October 23, 2013, the Company, along with the Bank, and Washington Banking Company (“Washington Banking”) and its wholly owned subsidiary bank, Whidbey Island Bank ("Whidbey") jointly announced the signing of a merger agreement under which Heritage and Washington Banking will enter into a strategic merger with Washington Banking merging into Heritage. Immediately following the merger, Whidbey will merge into the Bank. Washington Banking branches will adopt the Heritage Bank name in all markets, with the exception of six branches in Whidbey Island markets which will continue to operate using the Whidbey Island Bank name. The corporate headquarters of the combined company will be in Olympia, Washington.

Under the terms of the merger agreement, Washington Banking shareholders will receive 0.89000 shares of Heritage common stock and $2.75 in cash for each share of Washington Banking common stock. Based on the closing price of Heritage common stock of $15.89 on October 23, 2013, the consideration value per share for Washington Banking was $16.89, or approximately $265.1 million in aggregate. Upon consummation, the shareholders of Washington Banking will own approximately 46% of the combined company and the shareholders of Heritage will own approximately 54%. As of September 30, 2013, Washington Banking had approximately $1.6 billion in total assets.

The merger agreement has been unanimously approved by the boards of directors of Heritage and Washington Banking. The merger is subject to regulatory approvals, approval by Heritage and Washington Banking shareholders, and certain other customary closing conditions and is expected to close in the first half of 2014. The transaction is intended to qualify as a tax-free reorganization for U.S. federal income tax purposes and Washington Banking shareholders are not expected to recognize any taxable gain or loss in connection with the share exchange to the extent of the stock consideration received.

For further information, reference is made to the Form 8-K filed by the Company with the SEC on October 24, 2013.