Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Taxes [Abstract]
Income Taxes	‎ 11.    Income Taxes The provision for income taxes comprises the following (in thousands): For the Years Ended December 31, 2021 2020 2019Current U.S. federal$ 64,620  $ 58,602  $ 36,779 U.S. state and local 14,233  15,950  7,078 Foreign 511  539  600 Deferred U.S. federal, state and local 2,358  1,456  (2,773)Foreign 42  (23) 2 Total$ 81,764  $ 76,524  $ 41,686  A summary of the temporary differences that give rise to deferred tax assets/ (liabilities) follows (in thousands): December 31, 2021 2020 Accrued liabilities$ 42,840  $ 42,151  Lease liabilities 35,936  35,888  Implicit price concessions 7,744  7,031  Stock compensation expense 6,976  4,047  State net operating loss carryforwards 1,920  2,030  Other 920  888  Deferred income tax assets 96,336  92,035  Amortization of intangible assets (41,925) (40,619) Accelerated tax depreciation (35,416) (31,686) Right of use lease assets (32,489) (32,788) Currents assets (3,858) (3,921) Market valuation of investments (3,189) (2,382) State income taxes (2,504) (1,161) Other (138) (142) Deferred income tax liabilities (119,519) (112,699) Net deferred income tax liabilities$ (23,183) $ (20,664) At December 31, 2021 and 2020, state net operating loss carryforwards were $43.9 million and $37.3 million, respectively. These net operating losses will expire, in varying amounts, between 2026 and 2041. Based on our history of operating earnings, we have determined that our operating income will, more likely than not, be sufficient to ensure realization of our deferred income tax assets. A reconciliation of the beginning and ending of year amount of our unrecognized tax benefit is as follows (in thousands): 2021 2020 2019Balance at January 1,$ 1,304  $ 1,323  $ 1,348 Unrecognized tax benefits due to positions taken in current year 333  200  234 Decrease due to expiration of statute of limitations (258) (219) (259)Balance at December 31,$ 1,379  $ 1,304  $ 1,323  We file tax returns in the U.S. federal jurisdiction and various states. The years ended December 31, 2018 and forward remain open for review for federal income tax purposes. The earliest open year relating to any of our major state jurisdictions is the fiscal year ended December 31, 2016. During the next twelve months, we do not anticipate a material net change in unrecognized tax benefits. We classify interest related to our accrual for uncertain tax positions in separate interest accounts. As of December 31, 2021, and 2020, we have approximately $131,000 and $163,000, respectively, accrued in interest payable related to uncertain tax positions. These accruals are included in other current liabilities in the accompanying consolidated balance sheet. Net interest expense related to uncertain tax positions included in interest expense in the accompanying consolidated statement of income is not material. The difference between the actual income tax provision for continuing operations and the income tax provision calculated at the statutory U.S. federal tax rate is explained as follows (in thousands): For the Years Ended December 31, 2021 2020 2019 Income tax provision calculated using the statutory rate of 21%$ 73,566  $ 83,158  $ 54,938  Excess stock compensation tax benefits (9,884) (26,089) (24,177) State and local income taxes, less federal income tax effect 10,025  13,855  7,880  Nondeductible expenses 7,443  5,377  3,048  Other--net 614  223  (3) Income tax provision$ 81,764  $ 76,524  $ 41,686  Effective tax rate 23.3 % 19.3 % 15.9 % Summarized below are the total amounts of income taxes paid during the years ended December 31 (in thousands): 2021$ 99,430 2020 61,517 2019 44,063  Provision has not been made for additional taxes on $35.1 million of undistributed earnings of our domestic subsidiaries. Should we elect to sell our interest in these businesses rather than to affect a tax-free liquidation, additional taxes amounting to approximately $8.4 million would be incurred based on current income tax rates.