Long-term Debt Schedule of Debt Instruments (Details) (USD $)	6 Months Ended			6 Months Ended													3 Months Ended				0 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jun. 30, 2012 Senior secured revolving credit facility [Member]	Dec. 31, 2011 Senior secured revolving credit facility [Member]	Jun. 30, 2011 Senior secured revolving credit facility [Member]	Jun. 30, 2011 Senior secured revolving credit facility [Member] Minimum [Member]	Jun. 30, 2011 Senior secured revolving credit facility [Member] Maximum [Member]	Jul. 20, 2012 Senior secured revolving credit facility [Member] Future Period Analysis of Debt Instruments [Member]	Jun. 30, 2011 Senior secured revolving credit facility [Member] Alternative Testing for Covenant [Member] Minimum [Member]	Jun. 30, 2011 Senior secured revolving credit facility [Member] LIBOR [Member] Minimum [Member]	Jun. 30, 2011 Senior secured revolving credit facility [Member] LIBOR [Member] Maximum [Member]	Jul. 20, 2012 Senior secured revolving credit facility [Member] LIBOR [Member] Future Period Analysis of Debt Instruments [Member]	Jun. 30, 2011 Senior secured revolving credit facility [Member] Bank Prime Rate [Member] Minimum [Member]	Jun. 30, 2011 Senior secured revolving credit facility [Member] Bank Prime Rate [Member] Maximum [Member]	Jul. 20, 2012 Senior secured revolving credit facility [Member] Bank Prime Rate [Member] Future Period Analysis of Debt Instruments [Member]	Jun. 30, 2012 Senior Notes [Member]	Dec. 31, 2011 Senior Notes [Member]	Mar. 11, 2010 Senior Notes [Member]	Mar. 11, 2010 Senior Notes [Member] Redemption Prior to March 15, 2013 [Member]	Mar. 11, 2010 Senior Notes, 2010 [Member]	Nov. 21, 2011 Senior Notes, 2011 [Member]	Jun. 30, 2012 Notes Payable and Other [Member] [Member] Notes_Payable	Dec. 31, 2011 Notes Payable and Other [Member] [Member]	Jun. 30, 2012 Equipment [Member] Notes Payable and Other [Member] [Member]	Jun. 30, 2012 Notes Payable 1 [Member] Notes Payable and Other [Member] [Member]	Jun. 30, 2012 Notes Payable 2 [Member] Notes Payable and Other [Member] [Member]
Long-term Debt, by Current and Noncurrent [Abstract]
Long-term Debt	$ 454,161,000		$ 419,600,000	$ 35,000,000	$ 0												$ 418,170,000	$ 417,747,000					$ 991,000	$ 1,853,000
Less current portion	(871,000)		(872,000)
Long-term debt, less current portion	453,290,000		418,728,000
Line of Credit Facility [Abstract]
Line of Credit Facility, Maximum Borrowing Capacity						250,000,000
Debt Instrument, Basis Spread on Variable Rate											2.50%	3.25%	2.75%	1.50%	2.25%	1.75%
Debt Instrument, Stated Percentage of Outstanding Equity Interests of First-tier Foreign Subsidiaries That Secure Debt Obligations				65.00%
Line of Credit Facility, Amount Outstanding									35,000,000
Letters of Credit Outstanding, Amount									9,000,000
Line of Credit Facility, Remaining Borrowing Capacity									206,000,000
Ratio of Indebtedness to Net Capital				1.9
Ratio of Indebtedness to Net Capital, Senior				0.17
Ratio of Interest Coverage				8.0
Covenant Compliance, Ratio of Indebtedness to Net Capital								4.00
Covenant Compliance, Ratio of Indebtedness to Net Capital, Senior								2.50		2.00
Covenant Compliance, Ratio of Interest Coverage							2.50
Covenant Compliance, Ratio of Asset Coverage										1.00
Covenant Compliance, Line of Credit Facility, Remaining Borrowing Capacity After Capital Expenditures Adjustment To Avoid Future Capital Expenditures Restrictions										25,000,000
Covenant Compliance, Capital Expenditure Limitation Threshold, Ratio of Indebtedness to Net Capital, Senior								2.00
Capital Expenditure Limitation During Fiscal Year To Be Imposed If Covenant Noncompliance, Exceeding Stated Senior Consolidated Leverage Ratio				100,000,000
Capital Expenditure Limitation Maximum Amount Unused From Prior Fiscal Year Available to Increase Current Year Capital Expenditure Threshold If Restrictions Imposed Due to Noncompliance				30,000,000
Debt Instruments [Abstract]
Debt Instrument, Face Amount																	425,000,000				250,000,000	175,000,000
Debt Instrument, Interest Rate, Stated Percentage																					9.875%					6.00%	14.00%
Debt Instrument, Unamortized Discount																	8,400,000				10,600,000
Debt Instrument, Actual Value to Face Value, Percentage																					95.75%	101.00%
Debt Instrument, Interest Rate, Effective Percentage																					10.677%	9.66%
Proceeds from Issuance of Debt																					234,800,000	172,700,000
Deferred Finance Costs, Gross																					4,600,000	4,100,000
Debt Instrument, Unamortized Premium																	1,600,000					1,800,000
Debt Instrument, Redeemable with Equity Issuance Proceeds, Maximum Principal Percentage Redeemable per Occasion																				35.00%
Debt Instrument, Redeemable with Equity Inssuance Proceeds, Redemption Price, Percentage																				109.875%
Debt Instrument, Redeemable with Equity Issuance Proceeds, Minimum Percentage Outstanding After Redemption																			65.00%
Debt Instrument, Redeemable with Equity Issuance Proceeds, Redemption Term After Closing of Offering																	120 days
Debt Instrument, Redeemable with Equity Issuance Proceeds, Required Repurchase Due to Change in Control Redemption Price, Percentage																			101.00%
Debt Instrument, Redeemable with Equity Issuance Proceeds, Required Repurchase Due to Asset Disposition, Redemption Price, Percentage																			100.00%
Debt Instrument, Number of Debt Instruments																							2
Capital Lease Obligations																									100,000
Deferred Finance Costs, Net	10,600,000		11,600,000
Amortization of Financing Costs	$ 1,100,000	$ 1,000,000