Employee Benefit Plan	3 Months Ended
Mar. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit Plan The Company maintains a 401(k) retirement plan covering substantially all officers and employees of the Company, which permits participants to defer up to the maximum allowable amount determined by the IRS of their eligible compensation. As part of the Pension Plan termination in 2014, the Company directed the Pension Plan to transfer $7.9 million of the Pension Plan’s surplus assets into a suspense account in the Company’s 401(k) Plan. The Company has retained the risks and rewards of ownership of these assets; therefore, the assets held in the suspense account are included in the Company’s condensed consolidated financial statements until they are allocated to participants. As of March 31, 2018 and December 31, 2017, the fair value of these assets was recorded in restricted investments on the Company’s condensed consolidated balance sheets and were $3.4 million and $4.5 million, respectively. The Company expenses the fair value of the assets at the time the assets are allocated to participants, which is expected to be allocated up to the next three years. During the three months ended March 31, 2018 and 2017, the Company recorded an expense of $1.1 million and $1.2 million, respectively, for the fair value of the assets, less expenses, that were allocated to participants. Any gain or loss on these assets is reflected in the Company’s condensed consolidated statements of income and was less than a $0.1 million loss for the three months ended March 31, 2018 and less than a $0.1 million gain for the three months ended March 31, 2017. Refer to Note 5. Financial Instruments and Fair Value Measurements.

Employee Benefit Plan

The Company maintains a 401(k) retirement plan covering substantially all officers and employees of the Company, which permits participants to defer up to the maximum allowable amount determined by the IRS of their eligible compensation.

As part of the Pension Plan termination in 2014, the Company directed the Pension Plan to transfer $7.9 million of the Pension Plan’s surplus assets into a suspense account in the Company’s 401(k) Plan. The Company has retained the risks and rewards of ownership of these assets; therefore, the assets held in the suspense account are included in the Company’s condensed consolidated financial statements until they are allocated to participants. As of March 31, 2018 and December 31, 2017, the fair value of these assets was recorded in restricted investments on the Company’s condensed consolidated balance sheets and were $3.4 million and $4.5 million, respectively.

The Company expenses the fair value of the assets at the time the assets are allocated to participants, which is expected to be allocated up to the next three years. During the three months ended March 31, 2018 and 2017, the Company recorded an expense of $1.1 million and $1.2 million, respectively, for the fair value of the assets, less expenses, that were allocated to participants. Any gain or loss on these assets is reflected in the Company’s condensed consolidated statements of income and was less than a $0.1 million loss for the three months ended March 31, 2018 and less than a $0.1 million gain for the three months ended March 31, 2017. Refer to Note 5. Financial Instruments and Fair Value Measurements.