EARNINGS PER SHARE (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2012		Mar. 31, 2015		Mar. 31, 2014		Mar. 31, 2013
Weighted average number diluted shares outstanding adjustment [Abstract]
Restricted stock awards that contain non-forfeitable rights to dividends (in shares)																	0
Unexercised stock options																	$ 0
Basic and diluted common shares outstanding [Abstract]
Weighted average common shares outstanding - basic (in shares)																	7,318		7,927		7,810
Effect of dilutive shares (in shares)																	75		72		93
Weighted average shares common outstanding-diluted (in shares)																	7,393		7,999		7,903
Calculation of earnings per common share - basic [Abstract]
Net earnings	8,910,000		15,501,000		11,952,000		9,477,000		8,222,000		10,610,000		8,591,000		7,850,000		45,840,000		35,273,000		34,830,000
Net earnings attributable to participating securities																	59,000		307,000		668,000
Net earnings attributable to common share holders																	45,781,000		34,966,000		34,162,000
Earnings per common share - basic (in dollars per share)	$ 1.23	[1]	$ 2.14	[1]	$ 1.63	[1]	$ 1.26	[1]	$ 1.04	[1]	$ 1.33	[1]	$ 1.07	[1]	$ 0.98	[1]	$ 6.26	[1]	$ 4.41	[1]	$ 4.37
Calculation of earnings per common share - diluted [Abstract]
Net earnings attributable to common shareholders- basic																	45,781,000		34,966,000		34,162,000
Add: undistributed earnings attributable to participating securities																	1,000		3,000		4,000
Net earnings attributable to common shareholders- diluted																	$ 45,782,000		$ 34,969,000		$ 34,166,000
Earnings per share - diluted (in dollars per share)	$ 1.22	[1]	$ 2.13	[1]	$ 1.63	[1]	$ 1.25	[1]	$ 1.03	[1]	$ 1.32	[1]	$ 1.06	[1]	$ 0.97	[1]	$ 6.19	[1]	$ 4.37	[1]	$ 4.32

[1] Basic and diluted earnings per share are computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted per share information may not equal annual basic and diluted earnings per share.