CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net income	$ 24,196	$ 21,219
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	21,372	22,708
Deferred income taxes	(6,071)	2,949
Amortization of debt discount	870	822
Gain on disposal of assets	5,315	(1,416)
Stock-based compensation	2,848	5,196
Equity in earnings from unconsolidated affiliates less than dividends received	4,129	(1,393)
Tax benefit related to stock-based compensation	(404)	(101)
Increase (decrease) in cash resulting from changes in:
Accounts receivable	(10,081)	10,640
Inventories	(1,869)	(5,420)
Prepaid expenses and other assets	3,816	3,701
Accounts payable	960	(5,527)
Accrued liabilities	11,212	459
Other liabilities and deferred credits	(881)	(948)
Net cash provided by operating activities	55,412	52,889
Cash flows from investing activities:
Capital expenditures	(86,555)	(72,235)
Proceeds from asset dispositions	20,227	833
Investment in unconsolidated affiliate	850	0
Net cash used in investing activities	(67,178)	(71,402)
Cash flows from financing activities:
Proceeds from borrowings	0	55,000
Repayment of debt	(21,800)	(31,274)
Partial prepayment of put/call obligation	(17)	(15)
Common stock dividends paid	(7,145)	(5,410)
Issuance of common stock	311	1,183
Tax benefit related to stock-based compensation	404	101
Net cash provided by (used in) financing activities	(28,247)	19,585
Effect of exchange rate changes on cash and cash equivalents	5,713	(363)
Net increase (decrease) in cash and cash equivalents	(34,300)	709
Cash and cash equivalents at beginning of period	261,550	116,361
Cash and cash equivalents at end of period	227,250	117,070
Supplemental disclosure of cash flow information:
Interest	3,124	3,612
Income taxes	$ 6,498	$ 5,121