Business Combinations (Details) (USD $)	0 Months Ended	3 Months Ended								12 Months Ended			0 Months Ended	3 Months Ended	6 Months Ended
	Jul. 18, 2013	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jul. 18, 2013 HomeLink®	Dec. 31, 2013 HomeLink®	Dec. 31, 2013 HomeLink®	Dec. 31, 2013 Selling, General and Administrative Expenses HomeLink®	Dec. 31, 2013 Prepaid Expenses and Other HomeLink®
Business Acquisition [Line Items]
Purchase price													$ 700,000,000
Minimum term in business	10 years
Revenues		326,770,000	288,622,000	286,974,000	269,499,000	260,349,000	268,248,000	280,256,000	290,707,000	1,171,864,171	1,099,559,521	1,023,762,049		36,900,000	36,900,000
Gross profit		128,694,000	105,962,000	102,613,000	93,464,000	89,119,000	90,116,000	92,757,000	100,826,000	430,732,902	372,818,559	361,580,335		20,200,000	20,200,000
Cash paid to acquire business													423,000,000
Acquisition-related costs															3,300,000	2,300,000
Debt issuance cost																	$ 1,000,000