Operating Segment Information (Details 2) - USD ($) $ in Thousands	3 Months Ended											12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 235,625	$ 223,134	$ 245,131	$ 253,756	$ 228,588	$ 223,451	$ 256,890	$ 261,239	$ 248,344	$ 218,602	$ 249,236	$ 957,646	$ 970,168	$ 960,717
Long-lived assets	518,563				614,972				527,979			518,563	614,972	527,979
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues												791,451	814,803	847,708
Long-lived assets	360,203				404,723				317,887			360,203	404,723	317,887
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues												152,629	141,186	102,352
Long-lived assets	153,214				162,914				155,488			153,214	162,914	155,488
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues												13,566	12,640	10,657
Long-lived assets	3,787				4,755				10,199			3,787	4,755	10,199
U.K. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues												0	1,539	0
Long-lived assets	0				42,538				44,363			0	42,538	44,363
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 1,359				$ 42				$ 42			$ 1,359	$ 42	$ 42