TERM DEBT: (Details)	Feb. 23, 2016 USD ($)	Jun. 30, 2016 USD ($)
Debt Instrument [Line Items]
Debt instrument, issuance date	Feb. 22, 2016
Debt instrument, face amount	$ 280,000,000	$ 273,000,000
Debt instrument, maturity date	Feb. 21, 2019
Debt instrument, unamortized discount		(4,625,000)
Notes payable		$ 277,625,000
Interest rate, effective percentage		3.10%
Frequency of periodic payment	quarterly
Maturity date range, end	Feb. 21, 2019
2016 due in remaining six months		$ 14,000,000
2017		38,500,000
2018		63,000,000
2019		157,500,000
Debt, long-term and short-term, combined amount		$ 273,000,000
Debt issuance costs	$ 5,500,000
Pledge, percentage equity interest	1
Repayment terms	Quarterly amortization payments on the term loans of: (i) 2.50% of the original principal amount for the four fiscal quarters beginning on June 2016 and ending on March 2017, (ii)3.75% of the original principal amount for the four fiscal quarters beginning on June 2017 and ending on March 2018 and (iii) 6.25% of the original principal amount for the three fiscal quarters beginning on June 2018 and ending on December 2018. On the maturity date, the Company will be required to pay all remaining outstanding amounts under the term loans.
Eurodollar [Member]
Debt Instrument [Line Items]
Interest rate, stated percentage	1.00%
Description of variable rate basis	one-month Eurodollar rate
Base Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Description of variable rate basis	Base rate (which is the highest of (i) the administrative agent’s prime rate, (ii) one-half of 1.00% in excess of the overnight federal funds rate, and (iii) 1.00% in excess of the one-month Eurodollar rate), plus an applicable margin
Minimum [Member] | Eurodollar [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.25%
Minimum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.25%
Maximum [Member] | Eurodollar [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%
Maximum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
June 2016 To March 2017 [Member]
Debt Instrument [Line Items]
Periodic quarterly principal payment rate	2.50
Maturity date range, start	Jun. 30, 2016
Maturity date range, end	Mar. 31, 2017
June 2017 To March 2018 [Member]
Debt Instrument [Line Items]
Periodic quarterly principal payment rate	3.75
Maturity date range, start	Jun. 30, 2017
Maturity date range, end	Mar. 31, 2018
June 2018 To December 2018 [Member]
Debt Instrument [Line Items]
Periodic quarterly principal payment rate	6.25
Maturity date range, start	Jun. 30, 2018
Maturity date range, end	Dec. 31, 2018