LONG-TERM DEBT (Details) - Narrative $ / shares in Units, CAD in Thousands						1 Months Ended			3 Months Ended		12 Months Ended
	Oct. 02, 2017 USD ($)	Jan. 17, 2017 USD ($) shares	Oct. 01, 2016 USD ($)	Jul. 14, 2016 USD ($)	Mar. 22, 2016 USD ($)	Aug. 31, 2016 USD ($)	Jul. 31, 2016 USD ($)	Nov. 30, 2012 CAD	Dec. 31, 2017 USD ($) option $ / shares shares	Mar. 31, 2017 USD ($) shares	Sep. 30, 2016 USD ($)	Dec. 31, 2017 AUD	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CAD	Dec. 18, 2017 USD ($)	Sep. 30, 2017 AUD	Sep. 30, 2017 USD ($)	Mar. 31, 2017 AUD	Mar. 31, 2017 USD ($)	Jul. 31, 2016 AUD loan	May 18, 2016 USD ($)	Mar. 31, 2016 USD ($)	Sep. 30, 2015 USD ($)	Feb. 27, 2014 USD ($)	Feb. 14, 2014 USD ($)	Oct. 21, 2013 property	Dec. 21, 2009 USD ($)
Debt Instrument [Line Items]
Capitalized Fees & Expenses													$ 18,287,000				$ 12,066,000
Long-term debt													1,250,986,000				979,158,000
Face amount						$ 35,092,000																$ 8,000,000	$ 32,280,000
Underwriting fees and other expense capitalized											$ 10,313,000
Maximum percentage of equity interest of subsidiaries borrowings guaranteed									65.00%
Long-term line of credit													14,938,000
Number of properties refinanced | property																										4
Amount of line note available to purchase common stock in open market						$ 10,908,000
Stock issued during period, shares, employee stock ownership plan (in shares) | shares									621,875
Shares purchased for award value									$ 10,908,000
Weighted average purchase price of shares purchased | $ / shares									$ 17.54
Basis spread on variable rate								1.30%	1.30%
Number of option to extend | option									2
Lease renewal term									5 years
Convert. debt due 2017 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage																											4.00%
Face amount																											$ 100,000,000
Mortgages [Member]
Debt Instrument [Line Items]
Basis spread on variable rate									1.50%
Senior Notes [Member] | Senior Notes 2022 [Member]
Debt Instrument [Line Items]
Proceeds from issuance of debt	$ 275,000,000
Long-term debt													1,000,000,000
Senior Notes [Member] | Senior Notes due 2022, May 2016 Add-On Issuance [Member]
Debt Instrument [Line Items]
Debt issuance costs, net													3,016,000
Issuance price, percentage	101.00%																				98.76%
Face amount																					$ 125,000,000
Senior Notes 2022 [Member]
Debt Instrument [Line Items]
Capitalized Fees & Expenses															$ 8,434,000
Senior Notes 2022 [Member]
Debt Instrument [Line Items]
Capitalized Fees & Expenses													15,619,000				9,220,000
Debt instrument, interest rate, stated percentage	5.25%																							5.25%
Long-term debt													$ 985,865,000				$ 714,603,000
Face amount																								$ 600,000,000
Debt conversion, original debt, amount				$ 125,000,000
Debt instrument, interest rate, effective percentage												5.25%	5.25%	5.25%		5.25%	5.25%
Revolver due 2019 [Member]
Debt Instrument [Line Items]
Line of credit facility, current borrowing capacity																									$ 250,000,000
Revolver Due 2020 [Member]
Debt Instrument [Line Items]
Line of credit facility, current borrowing capacity					$ 350,000,000
Convertible Notes 2017 [Member]
Debt Instrument [Line Items]
Debt conversion, converted instrument, amount		$ 173,855,000								$ 173,855,000
Debt conversion, converted instrument, cash received		125,000,000								$ 125,000,000
Issuance of treasury stock in settlement of convertible debt		$ 48,858,000
Debt conversion, converted instrument, shares issued | shares		1,954,993								1,954,993
Debt instrument, interest rate, effective percentage		4.00%
Real estate mortgages [Member]
Debt Instrument [Line Items]
Capitalized Fees & Expenses													$ 304,000				$ 320,000
Long-term debt													22,743,000				23,322,000
Debt instrument, description of variable rate basis									The loans bear interest at a rate of LIBOR plus 1.50%
Basis spread on variable rate									2.25%
ESOP Loans [Member]
Debt Instrument [Line Items]
Capitalized Fees & Expenses													279,000				310,000
Long-term debt													41,827,000				42,365,000
Basis spread on variable rate									2.50%
Debt instrument, periodic payment, principal			$ 569,000
Capital lease - real estate [Member]
Debt Instrument [Line Items]
Capitalized Fees & Expenses													99,000				105,000
Long-term debt													$ 9,606,000				$ 5,207,000
Debt instrument, interest rate, effective percentage												5.00%	5.00%	5.00%		5.00%	5.00%
Non U.S. lines of credit [Member]
Debt Instrument [Line Items]
Capitalized Fees & Expenses													$ 27,000				$ 31,000
Long-term debt													4,648,000				9,371,000
Proceeds from long-term lines of credit								CAD 15,000	$ 11,901,000
Long-term line of credit													0
Remaining borrowing capacity													$ 11,901,000	CAD 15,000
Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, effective percentage												3.85%	3.85%	3.85%
Medium-term Notes [Member] | Term Loan Due 2019 [Member]
Debt Instrument [Line Items]
Periodic payment terms, balloon payment to be paid | AUD																				AUD 37,125,000
Number of loans refinanced with new debt instrument | loan																				2
Revolver Due 2013 [Member]
Debt Instrument [Line Items]
Basis spread on variable rate									1.75%
Fair Value, Inputs, Level 1 [Member] | Senior Notes 2022 [Member]
Debt Instrument [Line Items]
Convertible debt, fair value disclosures													$ 1,020,000,000
Libor Rate [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate during period					2.25%
Libor Rate [Member] | Non U.S. lines of credit [Member]
Debt Instrument [Line Items]
Interest rate at period end												2.98%	2.98%	2.98%
Bankers Acceptance Rate [Member] | Non U.S. lines of credit [Member]
Debt Instrument [Line Items]
Interest rate at period end												2.78%	2.78%	2.78%
Revolving Credit Facility [Member] | Revolving Facility, June 2017 [Member]
Debt Instrument [Line Items]
Long-term line of credit												AUD 6,000,000	$ 4,675,000
Maximum borrowing capacity | AUD												AUD 20,000								AUD 10,000,000
Revolver due 2019 [Member]
Debt Instrument [Line Items]
Long-term line of credit													147,743,000
Remaining borrowing capacity													$ 187,319,000
Revolver due 2019 [Member] | Letter Of Credit Subfacility [Member]
Debt Instrument [Line Items]
Line of credit facility, current borrowing capacity					$ 50,000,000
Revolver due 2019 [Member] | Multicurrency Subfacility [Member]
Debt Instrument [Line Items]
Line of credit facility, current borrowing capacity					$ 50,000,000
Revolver due 2019 [Member] | Margin Rate [Member]
Debt Instrument [Line Items]
Line of credit facility, interest rate during period					1.25%
London Interbank Offered Rate (LIBOR) [Member] | ESOP Loan July 2014 [Member]
Debt Instrument [Line Items]
Basis spread on variable rate									2.50%
Northcote Holdings Pty. Ltd [Member] | Non U.S. lines of credit [Member] | Line of Credit One [Member]
Debt Instrument [Line Items]
Basis spread on variable rate							2.00%
Debt instrument, interest rate, effective percentage												3.70%	3.70%	3.70%
Northcote Holdings Pty. Ltd [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Face amount | AUD																				AUD 30,000,000
Number of loans | loan																				2
Northcote Holdings Pty. Ltd [Member] | Term Loan May 2014 [Member]
Debt Instrument [Line Items]
Face amount | AUD																				AUD 10,000,000
Debt instrument, periodic payment, principal							$ 1,250,000
Maximum borrowing capacity																	$ 46,750,000	AUD 5,000,000	$ 33,500,000
Maximum borrowing capacity increase | AUD																AUD 15,000,000
Northcote Holdings Pty. Ltd [Member] | Term Loan December 2013 and May 2014 [Member]
Debt Instrument [Line Items]
Long-term line of credit												AUD 44,625,000	$ 34,765,000
Basis spread on variable rate							2.00%
Debt instrument, interest rate, effective percentage												3.84%	3.84%	3.84%
Troy, Ohio [Member]
Debt Instrument [Line Items]
Percentage bearing fixed interest, percentage rate												5.00%	5.00%	5.00%
Ocala, Florida [Member]
Debt Instrument [Line Items]
Percentage bearing fixed interest, percentage rate												8.00%	8.00%	8.00%