Stock Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option expense	$ 517		$ 303	$ 925	$ 619
Weighted-average fair value per share (in dollars per share)	$ 5.43			$ 5.53
Number of Shares [Roll Forward]
Outstanding, beginning balance (in shares)	2,156,850	2,264,399		2,264,399
Granted (in shares)	105,735	10,000
Exercised (in shares)	(147,900)	(114,599)
Forfeited or expired (in shares)	0	(2,950)
Outstanding, ending balance (in shares)	2,114,685	2,156,850		2,114,685
Options exercisable (in shares)	1,050,800			1,050,800
Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning balance (in dollars per share)	$ 7.13	$ 7.02		$ 7.02
Granted (in dollars per share)	$ 12.94	$ 11.44
Exercised (in dollars per share)	$ 5.46	$ 5.40
Forfeited or expired (in dollars per share)	$ 0	$ 10.42
Outstanding, ending balance (in dollars per share)	$ 7.53	$ 7.13		$ 7.53
Exercisable, ending balance (in dollars per share)	$ 6.16			$ 6.16
Aggregate intrinsic value exercised	1,123		17	1,889	50
Aggregate intrinsic value outstanding	13,612			13,612
Aggregate intrinsic value exercisable	8,205			8,205
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock expense	139		134	161	175
Nonvested Restricted Stock Number of Shares [Roll Forward]
Nonvested, beginning balance (in shares)	1,695	31,145		31,145
Granted (in shares)	31,648	0
Vested during period (in shares)	(1,695)	(29,450)
Forfeited (in shares)	0	0
Nonvested, ending balance (in shares)	31,648	1,695		31,648
Nonvested Restricted Stock, Weighted-Average Grant-Date Fair Value [Roll Forward]
Nonvested, beginning balance (in dollars per share)	$ 9.64	$ 5.76		$ 5.76
Granted (in dollars per share)	$ 12.64	$ 0
Vested during period (in dollars per share)	$ 9.64	$ 5.54
Forfeited (in dollars per share)	$ 0	$ 0
Nonvested, ending balance (in dollars per share)	$ 12.64	$ 9.64		$ 12.64
Compensation cost and weighted average vesting period information [Line Items]
Total compensation cost related to unvested share-based awards not yet recognized	267			267
Weighted average vesting period	3 months 18 days
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	3 years
Performance Shares [Member] | Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share expense	93			156
Cash Settled Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	3 years
Cash Settled Performance Share Units [Member] | Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share unit expense	320		424	861	400
Nonvested Stock Option [Member]
Compensation cost and weighted average vesting period information [Line Items]
Total compensation cost related to unvested share-based awards not yet recognized	$ 4,030			$ 4,030
Weighted average vesting period	2 years 3 months 18 days
Nonvested Stock Options, Number of Shares [Roll Forward]
Nonvested, beginning balance (in shares)	1,013,776	1,029,776		1,029,776
Granted (in shares)	105,735	10,000
Vested during period (in shares)	(55,626)	(25,000)
Forfeited (in shares)	0	(1,000)
Nonvested, ending balance (in shares)	1,063,885	1,013,776		1,063,885
Nonvested Stock Options, Weighted-Average Grant-Date Fair Value [Roll Forward]
Nonvested, beginning balance (in dollars per share)	$ 4.69	$ 4.62		$ 4.62
Granted (in dollars per share)	$ 5.43	$ 6.55
Vested during period (in dollars per share)	$ 2.43	$ 2.69
Forfeited (in dollars per share)	$ 0	$ 3.39
Nonvested, ending balance (in dollars per share)	$ 4.88	$ 4.69		$ 4.88