STOCK-BASED COMPENSATION - Restricted Stock and Restricted Stock units Activity (Details)	6 Months Ended
Jun. 30, 2016 $ / shares shares
Service Period \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock
Number of Shares
Unvested awards outstanding at January 1, 2016 \| shares	306,839
Awards granted \| shares	4,925.00
Awards vested \| shares	(127,529)
Awards forfeited/cancelled \| shares	(582)
Unvested awards outstanding at March 31, 2016 \| shares	183,653
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2016 \| $ / shares	$ 41.14
Awards granted \| $ / shares	76.18
Awards vested \| $ / shares	41.53
Awards forfeited/cancelled \| $ / shares	36.57
Unvested awards outstanding at March 31, 2016 \| $ / shares	$ 41.82
Service Period \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock Units
Number of Shares
Unvested awards outstanding at January 1, 2016 \| shares	149,272
Awards granted \| shares	386,205
Awards vested \| shares	(31,348)
Awards forfeited/cancelled \| shares	(13,734)
Unvested awards outstanding at March 31, 2016 \| shares	490,395
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2016 \| $ / shares	$ 57.55
Awards granted \| $ / shares	70.50
Awards vested \| $ / shares	50.80
Awards forfeited/cancelled \| $ / shares	70.95
Unvested awards outstanding at March 31, 2016 \| $ / shares	$ 67.80
Service Period \| Liability Classified Award \| Cash-Settled Award \| Restricted Stock Units
Number of Shares
Unvested awards outstanding at January 1, 2016 \| shares	0
Awards granted \| shares	207,586
Awards vested \| shares	0
Awards forfeited/cancelled \| shares	(1,372)
Unvested awards outstanding at March 31, 2016 \| shares	206,214
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2016 \| $ / shares	$ 0.00
Awards granted \| $ / shares	70.53
Awards vested \| $ / shares	0.00
Awards forfeited/cancelled \| $ / shares	70.52
Unvested awards outstanding at March 31, 2016 \| $ / shares	$ 70.53
Performance Target \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock
Number of Shares
Unvested awards outstanding at January 1, 2016 \| shares	22,090
Awards granted \| shares	0
Awards vested \| shares	(6,784)
Awards forfeited/cancelled \| shares	(6,306)
Unvested awards outstanding at March 31, 2016 \| shares	9,000
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2016 \| $ / shares	$ 37.52
Awards granted \| $ / shares	0.00
Awards vested \| $ / shares	36.57
Awards forfeited/cancelled \| $ / shares	36.57
Unvested awards outstanding at March 31, 2016 \| $ / shares	$ 38.90
Performance Target \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock Units
Number of Shares
Unvested awards outstanding at January 1, 2016 \| shares	14,000
Awards granted \| shares	0
Awards vested \| shares	(4,666)
Awards forfeited/cancelled \| shares	0
Unvested awards outstanding at March 31, 2016 \| shares	9,334
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2016 \| $ / shares	$ 70.22
Awards granted \| $ / shares	0.00
Awards vested \| $ / shares	70.22
Awards forfeited/cancelled \| $ / shares	0.00
Unvested awards outstanding at March 31, 2016 \| $ / shares	$ 70.22
Performance Target \| Liability Classified Award \| Equity-Settled Award \| Restricted Stock Units
Number of Shares
Unvested awards outstanding at January 1, 2016 \| shares	211,206
Awards granted \| shares	0
Awards vested \| shares	(105,604)
Awards forfeited/cancelled \| shares	0
Unvested awards outstanding at March 31, 2016 \| shares	105,602
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2016 \| $ / shares	$ 39.65
Awards granted \| $ / shares	0.00
Awards vested \| $ / shares	40.44
Awards forfeited/cancelled \| $ / shares	0.00
Unvested awards outstanding at March 31, 2016 \| $ / shares	$ 38.86

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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+ References

No definition available.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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