CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Revenues	$ 555,117		$ 433,799		$ 334,528
Operating expenses:
Cost of revenues (exclusive of depreciation and amortization)	347,650		270,361		205,336
Selling, general and administrative expenses	116,497		85,868		64,930
Depreciation and amortization expense	15,120		10,882		7,538
Goodwill impairment loss	0		0		1,697
Other operating (income)/ expenses, net	(643)		682		19
Income from operations	76,493		66,006		55,008
Interest and other income, net	3,077		1,941		1,422
Foreign exchange loss	(2,800)		(2,084)		(3,638)
Total	76,770		65,863		52,792
Provision for income taxes	14,776		11,379		8,439
Net income	61,994		54,484		44,353
Cumulative translation adjustment	(811)		2,493		(1,250)
Comprehensive income	61,183		56,977		43,103
Accretion of preferred stock	0		0		(17,563)
Net income allocated to participating securities	0		(3,341)		(15,025)
Net income available for common stockholders	61,994		51,143		11,765
Net income per share of common stock:
Basic (in dollars per share)	$ 1.35	[1]	$ 1.27	[1]
Diluted (in dollars per share)	$ 1.28	[1]	$ 1.17	[1]
Weighted Average Number of Shares Outstanding, Basic	45,754		40,190		17,094
Weighted Average Number of Shares Outstanding, Diluted	48,358		43,821		20,473
Common Stock [Member]
Operating expenses:
Net income	61,994		54,484		44,353
Net income available for common stockholders	61,994		51,143		11,765
Net income per share of common stock:
Basic (in dollars per share)	$ 1.35		$ 1.27		$ 0.69
Diluted (in dollars per share)	$ 1.28		$ 1.17		$ 0.63
Weighted Average Number of Shares Outstanding, Basic	45,754,000		40,190,000		17,094,000
Weighted Average Number of Shares Outstanding, Diluted	48,358,000		43,821,000		20,473,000
Puttable Common Stock [Member]
Operating expenses:
Net income available for common stockholders	$ 0		$ 0		$ 26
Net income per share of common stock:
Basic (in dollars per share)	$ 0		$ 0		$ 1.42
Diluted (in dollars per share)	$ 0		$ 0		$ 0.77
Weighted Average Number of Shares Outstanding, Basic	0		0		18,000
Weighted Average Number of Shares Outstanding, Diluted	0		0		18,000

[1] Earnings per share amounts for each quarter may not necessarily total to the yearly earnings per share due to the weighting of shares outstanding on a quarterly and year-to-date basis.