CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - Parenthetical - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Stockholders' Equity [Abstract]
Actuarially Determined Long-Term Liability Adjustments, Tax	$ 780	$ 781	$ 781	$ 1,232	$ 1,183	$ 1,281	$ 2,342	$ 3,697
Repurchase of Common Stock (in shares)	1,366,054	351,443		190,272	47,000	44,000	1,717,497	281,272
Interest Rate Hedge, Tax	$ (83)	$ (84)		$ 0			$ (167)	$ 0
Purchase of CCR Units (in units)	19,413	6,884		77,536

Amount of tax expense (benefit) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount of tax expense (benefit) for reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Number of shares that have been repurchased and retired during the period.

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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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