Description of the business and recent developments: (Tables)

6 Months Ended

Jun. 30, 2021

Description of the business and recent developments:

Schedule of diluted weighted average shares

	Three Months Ended	Three Months Ended	Six Months Ended	Six Months Ended
	June 30, 2021	June 30, 2020	June 30, 2021	June 30, 2020
Weighted average common shares - basic	46,229,603	45,754,880	46,227,528	45,760,302
Dilutive effect of stock options	—	205,823	33,084	128,477
Dilutive effect of restricted stock	—	725,962	483,458	703,666
Weighted average common shares - diluted	46,229,603	46,686,665	46,744,070	46,592,445

Schedule of unvested and anti-dilutive shares

	Three Months	Three Months	Six Months	Six Months
	Ended	Ended	Ended	Ended
	June 30, 2021	June 30, 2020	June 30, 2021	June 30, 2020
Unvested shares of restricted common stock	1,420,759	1,521,942	1,420,759	1,521,942
Anti-dilutive options for common stock	36,063	18,496	56,022	13,172
Anti-dilutive shares of restricted common stock	28,019	—	181,265	—

Schedule of Stockholders' Deficit

The following details the changes in stockholder’s deficit for the three and six months ended June 30, 2021 and June 30, 2020 (in thousands except share amounts):

						Accumulated
				Additional		Other				Total
	Common Stock			Paid-in		Comprehensive		Accumulated		Stockholder’s
	Shares	Amount		Capital		Income (Loss)		Deficit		Equity (Deficit)
Balance at March 31, 2020	47,139,369	$	47	$	499,455	$	(15,819)	$	(705,908)	$	(222,225)
Forfeitures of shares granted to employees	(972)		—		—		—		—		—
Equity-based compensation	—		—		6,666		—		—		6,666
Foreign currency translation	—		—		—		2,913		—		2,913
Issuances of common stock	135,280		—		—		—		—		—
Exercises of options	5,524		—		270		—		—		270
Dividends paid	—		—		—		—		(31,738)		(31,738)
Net income	—		—		—		—		8,564		8,564
Balance at June 30, 2020	47,279,201	$	47	$	506,391	$	(12,906)	$	(729,082)	$	(235,550)

						Accumulated
				Additional		Other				Total
	Common Stock			Paid-in		Comprehensive		Accumulated		Stockholder’s
	Shares	Amount		Capital		Income (Loss)		Deficit		Equity (Deficit)
Balance at March 31, 2021	47,522,672	$	48	$	523,913	$	(6,516)	$	(825,004)	$	(307,559)
Forfeitures of shares granted to employees	(5,626)		—		—		—		—		—
Equity-based compensation	—		—		8,476		—		—		8,476
Foreign currency translation	—		—		—		1,776		—		1,776
Issuances of common stock	125,060		—		—		—		—		—
Exercises of options	13,025		—		660		—		—		660
Dividends paid	—		—		—		—		(37,001)		(37,001)
Net loss	—		—		—		—		(2,493)		(2,493)
Balance at June 30, 2021	47,655,131	$	48	$	533,049	$	(4,740)	$	(864,498)	$	(336,141)

						Accumulated
				Additional		Other				Total
	Common Stock			Paid-in		Comprehensive		Accumulated		Stockholder’s
	Shares	Amount		Capital		Income (Loss)		Deficit		Equity (Deficit)
Balance at December 31, 2019	46,840,434	$	47	$	493,178	$	(12,326)	$	(684,578)	$	(203,679)
Forfeitures of shares granted to employees	(37,280)		—		—		—		—		—
Equity-based compensation	—		—		12,224		—		—		12,224
Foreign currency translation	—		—		—		(580)		—		(580)
Issuances of common stock	455,030		—		—		—		—		—
Exercises of options	21,017		—		989		—		—		989
Dividends paid	—		—		—		—		(62,295)		(62,295)
Net income	—		—		—		—		17,791		17,791
Balance at June 30, 2020	47,279,201	$	47	$	506,391	$	(12,906)	$	(729,082)	$	(235,550)

						Accumulated
				Additional		Other				Total
	Common Stock			Paid-in		Comprehensive		Accumulated		Stockholder's
	Shares	Amount		Capital		Income (Loss)		Deficit		Equity (Deficit)
Balance at December 31, 2020	47,214,077	$	47	$	515,867	$	(1,306)	$	(807,774)	$	(293,166)
Forfeitures of shares granted to employees	(25,302)		—		—		—		—		—
Equity-based compensation	—		—		16,307		—		—		16,307
Foreign currency translation	—		—		—		(3,434)		—		(3,434)
Issuances of common stock	448,760		1		—		—		—		1
Exercises of options	17,596		—		875		—		—		875
Dividends paid	—		—		—		—		(73,082)		(73,082)
Net income	—		—		—		—		16,358		16,358
Balance at June 30, 2021	47,655,131	$	48	$	533,049	$	(4,740)	$	(864,498)	$	(336,141)

Schedule of lease cost

	Three Months		Three Months		Six Months		Six Months
	Ended		Ended		Ended		Ended
	June 30, 2021		June 30, 2020		June 30, 2021		June 30, 2020
Finance lease cost
Amortization of right-of-use assets	$	6,378	$	4,973	$	12,724	$	9,735
Interest expense on finance lease liabilities		4,685		4,517		9,911		8,990
Operating lease cost		4,671		4,405		9,088		8,592
Total lease costs	$	15,734	$	13,895	$	31,723	$	27,317

	Six Months			Six Months
	Ended			Ended
	June 30, 2021			June 30, 2020
Other lease information
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from finance leases	$	(10,111)		$	(8,985)
Operating cash flows from operating leases		(10,104)			(9,149)
Financing cash flows from finance leases		(11,936)			(9,883)
Right-of-use assets obtained in exchange for new finance lease liabilities		16,218			42,359
Right-of-use assets obtained in exchange for new operating lease liabilities		12,531			20,694
Weighted-average remaining lease term — finance leases (in years)		12.5			12.1
Weighted-average remaining lease term — operating leases (in years)		19.4			20.4
Weighted average discount rate — finance leases		9.8	%		10.8	%
Weighted average discount rate — operating leases		5.5	%		5.4	%

Schedule of future minimum payments under finance leases

Schedule of future minimum payments under operating lease agreements

The future minimum payments under these operating lease and finance lease agreements are as follows (in thousands):

	OPERATING		FINANCE
For the twelve months ending June 30,	LEASES		LEASES
2022	$	18,448	$	34,461
2023		18,030		33,569
2024		17,382		32,917
2025		15,678		32,573
2026		13,140		25,420
Thereafter		118,278		235,307
Total minimum lease obligations		200,956		394,247
Less—amounts representing interest		(73,224)		(169,655)
Present value of minimum lease obligations		127,732		224,592
Current maturities		(11,783)		(16,004)
Lease obligations, net of current maturities	$	115,949	$	208,588

Schedule of impact on financial statement line items from adopting ASC 326

			Current-period
			Provision for		Write offs
	Beginning		Expected Credit		Charged Against		Ending
Description	Balance		Losses		Allowance		Balance
Allowance for credit losses (deducted from accounts receivable)
Three months ending June 30, 2021	$	1,457	$	1,187	$	(971)	$	1,673
Three months ending June 30, 2020	$	1,976	$	1,432	$	(1,293)	$	2,115
Six months ending June 30, 2021	$	1,921	$	3,199	$	(3,447)	$	1,673
Six months ending June 30, 2020	$	1,771	$	2,768	$	(2,424)	$	2,115